i. hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/serra-negra 1.pdfi....
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![Page 1: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/1.jpg)
§0 §1 §2 §3 §4 §5
I. Hölder continuous solutions of a class ofplanar vector fields
Hamid Meziani
Florida International University
Geometric Analysis of PDE and Several Complex Variables,Serra Negra, SP, Brazil, 2015
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References about solvability of systems of vector fields
S. Berhanu, P. Cordaro, J. Hounie: An introduction toinvolutive structures, New Math. Mono., 6, CambridgeUniversity Press, Cambridge, (2008)F. Treves, Hypo-Analytic Structures: Local Theory,Princeton Mathematical Series, 40, Princeton Univ. Press,NJ (1992)
![Page 3: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/3.jpg)
§0 §1 §2 §3 §4 §5
References about solvability of systems of vector fields
S. Berhanu, P. Cordaro, J. Hounie: An introduction toinvolutive structures, New Math. Mono., 6, CambridgeUniversity Press, Cambridge, (2008)F. Treves, Hypo-Analytic Structures: Local Theory,Princeton Mathematical Series, 40, Princeton Univ. Press,NJ (1992)
![Page 4: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/4.jpg)
§0 §1 §2 §3 §4 §5
References about solvability of systems of vector fields
S. Berhanu, P. Cordaro, J. Hounie: An introduction toinvolutive structures, New Math. Mono., 6, CambridgeUniversity Press, Cambridge, (2008)F. Treves, Hypo-Analytic Structures: Local Theory,Princeton Mathematical Series, 40, Princeton Univ. Press,NJ (1992)
![Page 5: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/5.jpg)
§0 §1 §2 §3 §4 §5
Discuss a class of planar vector fields in R2 that haveanalogous properties as those of ∂.
Hölder solvability:
∂u = f , f ∈ Lp, p > 2 ⇒ u ∈ Cα, α =p − 2
p
Integral representation: u =−1π
∫Ω
f (ζ
ζ − zdξdη + H(z)
Similarity Principle: ∂u = Au + Bu ⇒ u(z) = H(z)es(z)
Boundary value problem (RH):∂u = Au + Bu + f in Ω , Re(λu) = φ on ∂Ω.
![Page 6: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/6.jpg)
§0 §1 §2 §3 §4 §5
Discuss a class of planar vector fields in R2 that haveanalogous properties as those of ∂.
Hölder solvability:
∂u = f , f ∈ Lp, p > 2 ⇒ u ∈ Cα, α =p − 2
p
Integral representation: u =−1π
∫Ω
f (ζ
ζ − zdξdη + H(z)
Similarity Principle: ∂u = Au + Bu ⇒ u(z) = H(z)es(z)
Boundary value problem (RH):∂u = Au + Bu + f in Ω , Re(λu) = φ on ∂Ω.
![Page 7: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/7.jpg)
§0 §1 §2 §3 §4 §5
Discuss a class of planar vector fields in R2 that haveanalogous properties as those of ∂.
Hölder solvability:
∂u = f , f ∈ Lp, p > 2 ⇒ u ∈ Cα, α =p − 2
p
Integral representation: u =−1π
∫Ω
f (ζ
ζ − zdξdη + H(z)
Similarity Principle: ∂u = Au + Bu ⇒ u(z) = H(z)es(z)
Boundary value problem (RH):∂u = Au + Bu + f in Ω , Re(λu) = φ on ∂Ω.
![Page 8: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/8.jpg)
§0 §1 §2 §3 §4 §5
Discuss a class of planar vector fields in R2 that haveanalogous properties as those of ∂.
Hölder solvability:
∂u = f , f ∈ Lp, p > 2 ⇒ u ∈ Cα, α =p − 2
p
Integral representation: u =−1π
∫Ω
f (ζ
ζ − zdξdη + H(z)
Similarity Principle: ∂u = Au + Bu ⇒ u(z) = H(z)es(z)
Boundary value problem (RH):∂u = Au + Bu + f in Ω , Re(λu) = φ on ∂Ω.
![Page 9: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/9.jpg)
§0 §1 §2 §3 §4 §5
Discuss a class of planar vector fields in R2 that haveanalogous properties as those of ∂.
Hölder solvability:
∂u = f , f ∈ Lp, p > 2 ⇒ u ∈ Cα, α =p − 2
p
Integral representation: u =−1π
∫Ω
f (ζ
ζ − zdξdη + H(z)
Similarity Principle: ∂u = Au + Bu ⇒ u(z) = H(z)es(z)
Boundary value problem (RH):∂u = Au + Bu + f in Ω , Re(λu) = φ on ∂Ω.
![Page 10: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/10.jpg)
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Necessary and Sufficient condition for local solvability given byNirenberg-Treves Condition (P)For nonsingular planar vector fields L. We can find localcoordinates such that
L = m(x , t)(∂
∂t− ib(x , t)
∂
∂x
)with b an R-valued function. Condition (P) just means that forevery x , the function t −→ b(x , t) does not change sign.
Example.∂
∂t− ixntm ∂
∂xwith m ∈ Z+ satisfies (P) iff m is even.
![Page 11: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/11.jpg)
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Necessary and Sufficient condition for local solvability given byNirenberg-Treves Condition (P)For nonsingular planar vector fields L. We can find localcoordinates such that
L = m(x , t)(∂
∂t− ib(x , t)
∂
∂x
)with b an R-valued function. Condition (P) just means that forevery x , the function t −→ b(x , t) does not change sign.
Example.∂
∂t− ixntm ∂
∂xwith m ∈ Z+ satisfies (P) iff m is even.
![Page 12: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/12.jpg)
§0 §1 §2 §3 §4 §5
Necessary and Sufficient condition for local solvability given byNirenberg-Treves Condition (P)For nonsingular planar vector fields L. We can find localcoordinates such that
L = m(x , t)(∂
∂t− ib(x , t)
∂
∂x
)with b an R-valued function. Condition (P) just means that forevery x , the function t −→ b(x , t) does not change sign.
Example.∂
∂t− ixntm ∂
∂xwith m ∈ Z+ satisfies (P) iff m is even.
![Page 13: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/13.jpg)
§0 §1 §2 §3 §4 §5
Necessary and Sufficient condition for local solvability given byNirenberg-Treves Condition (P)For nonsingular planar vector fields L. We can find localcoordinates such that
L = m(x , t)(∂
∂t− ib(x , t)
∂
∂x
)with b an R-valued function. Condition (P) just means that forevery x , the function t −→ b(x , t) does not change sign.
Example.∂
∂t− ixntm ∂
∂xwith m ∈ Z+ satisfies (P) iff m is even.
![Page 14: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/14.jpg)
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If L satisfies (P), then it is locally integrable.Given point p, there is U open p ∈ U and Z : U −→ C suchthat
LZ = 0 and dZ 6= 0 in U
In fact we can assume
Z (x , t) = x + iφ(x , t)
L = m(
(1 + iφx )∂
∂x− iφt
∂
∂t
)
![Page 15: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/15.jpg)
§0 §1 §2 §3 §4 §5
If L satisfies (P), then it is locally integrable.Given point p, there is U open p ∈ U and Z : U −→ C suchthat
LZ = 0 and dZ 6= 0 in U
In fact we can assume
Z (x , t) = x + iφ(x , t)
L = m(
(1 + iφx )∂
∂x− iφt
∂
∂t
)
![Page 16: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/16.jpg)
§0 §1 §2 §3 §4 §5
If L satisfies (P), then it is locally integrable.Given point p, there is U open p ∈ U and Z : U −→ C suchthat
LZ = 0 and dZ 6= 0 in U
In fact we can assume
Z (x , t) = x + iφ(x , t)
L = m(
(1 + iφx )∂
∂x− iφt
∂
∂t
)
![Page 17: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/17.jpg)
§0 §1 §2 §3 §4 §5
If L satisfies (P), then it is locally integrable.Given point p, there is U open p ∈ U and Z : U −→ C suchthat
LZ = 0 and dZ 6= 0 in U
In fact we can assume
Z (x , t) = x + iφ(x , t)
L = m(
(1 + iφx )∂
∂x− iφt
∂
∂t
)
![Page 18: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/18.jpg)
§0 §1 §2 §3 §4 §5
If L satisfies (P), then it is locally integrable.Given point p, there is U open p ∈ U and Z : U −→ C suchthat
LZ = 0 and dZ 6= 0 in U
In fact we can assume
Z (x , t) = x + iφ(x , t)
L = m(
(1 + iφx )∂
∂x− iφt
∂
∂t
)
![Page 19: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/19.jpg)
§0 §1 §2 §3 §4 §5
We know if L satisfies (P) and has C∞ coefficients, then L issolvable in C∞ category:
Lu = f has C∞ solutions if f ∈ C∞ .
An old result of Treves gives L2-solvability. There isLp-solvability in 2 variables under only Lipschitz regularity ofcoefficients of L [Hounie-Morales Melo] (97)
Lu = f has Lp solutions if f ∈ Lp .
Example.∂
∂t− ix
∂
∂xsatisfies (P) with first integral Z = xeit .
However Lu = 0 has singular solutions. For instanceu = ln|x |+ it .
![Page 20: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/20.jpg)
§0 §1 §2 §3 §4 §5
We know if L satisfies (P) and has C∞ coefficients, then L issolvable in C∞ category:
Lu = f has C∞ solutions if f ∈ C∞ .
An old result of Treves gives L2-solvability. There isLp-solvability in 2 variables under only Lipschitz regularity ofcoefficients of L [Hounie-Morales Melo] (97)
Lu = f has Lp solutions if f ∈ Lp .
Example.∂
∂t− ix
∂
∂xsatisfies (P) with first integral Z = xeit .
However Lu = 0 has singular solutions. For instanceu = ln|x |+ it .
![Page 21: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/21.jpg)
§0 §1 §2 §3 §4 §5
We know if L satisfies (P) and has C∞ coefficients, then L issolvable in C∞ category:
Lu = f has C∞ solutions if f ∈ C∞ .
An old result of Treves gives L2-solvability. There isLp-solvability in 2 variables under only Lipschitz regularity ofcoefficients of L [Hounie-Morales Melo] (97)
Lu = f has Lp solutions if f ∈ Lp .
Example.∂
∂t− ix
∂
∂xsatisfies (P) with first integral Z = xeit .
However Lu = 0 has singular solutions. For instanceu = ln|x |+ it .
![Page 22: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/22.jpg)
§0 §1 §2 §3 §4 §5
We know if L satisfies (P) and has C∞ coefficients, then L issolvable in C∞ category:
Lu = f has C∞ solutions if f ∈ C∞ .
An old result of Treves gives L2-solvability. There isLp-solvability in 2 variables under only Lipschitz regularity ofcoefficients of L [Hounie-Morales Melo] (97)
Lu = f has Lp solutions if f ∈ Lp .
Example.∂
∂t− ix
∂
∂xsatisfies (P) with first integral Z = xeit .
However Lu = 0 has singular solutions. For instanceu = ln|x |+ it .
![Page 23: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/23.jpg)
§0 §1 §2 §3 §4 §5
We know if L satisfies (P) and has C∞ coefficients, then L issolvable in C∞ category:
Lu = f has C∞ solutions if f ∈ C∞ .
An old result of Treves gives L2-solvability. There isLp-solvability in 2 variables under only Lipschitz regularity ofcoefficients of L [Hounie-Morales Melo] (97)
Lu = f has Lp solutions if f ∈ Lp .
Example.∂
∂t− ix
∂
∂xsatisfies (P) with first integral Z = xeit .
However Lu = 0 has singular solutions. For instanceu = ln|x |+ it .
![Page 24: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/24.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 25: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/25.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 26: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/26.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 27: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/27.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 28: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/28.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 29: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/29.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 30: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/30.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 31: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/31.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 32: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/32.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 33: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/33.jpg)
§0 §1 §2 §3 §4 §5
In order to gain regularity of solutions, it is necessary toassume that L does not have 1-dimensional orbits.Assume that L is hypocomplex. L satisfies (P) and the local firstintegrals are homeomorphisms.
Example.∂
∂t− ix
∂
∂xis not hypocomplex.
∂
∂t− 3it2 ∂
∂xis hypocomplex since its first integral Z = x + it3 is
global homeomorphism.Hypocomplexity is not enough.Example. [Berhanu-Cordaro-Hounie].
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x, Z (x , t) = x + i
|t |t
exp−1|t |
.
L is a C∞ hypocomplex vector field with first integral Z . Let
S = (x , t) : |Z (x , t)| < 1/2, 0 < arg(Z (x , t)) < π/4 .
For f = characteristic function of S, the equation Lu = f has nobounded solutions.
![Page 34: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/34.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 35: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/35.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 36: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/36.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 37: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/37.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 38: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/38.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 39: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/39.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 40: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/40.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 41: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/41.jpg)
§0 §1 §2 §3 §4 §5
Łojasiewicz type condition
Given L, let Σ be the characteristic set of L
Σ = p : Lp ∧ Lp = 0
L satisfies the Łojasiewicz type condition (LC) if for everyp ∈ Σ, L has a local first integral Z = x + iφ(x , t) (withZ (p) = 0) defined in an open set p ∈ U ⊂ R2such that Z is ahomeomorphism and satisfyies
|φ(x , t)|σ ≤ C|φt (x , t)|
for some C > 0 and σ ∈ (0, 1).Remark. The (LC) condition is invariant under change ofcoordinates or choice of a local first integral.Remark. If Σ is 1-dimensional manifold, then the (LC) conditioncan be written as
dis(Z (m),Z (Σ))σ ≤ C|Im(ZxZ y )| .
![Page 42: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/42.jpg)
§0 §1 §2 §3 §4 §5
Example. If L is of uniform finite type n along Σ, then L satisfies(LC) with σ =
nn + 1
.
Example. The vector field
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x
does not satisfy (LC) since
limt→0
t2 exp1− σ|t |
=∞ if σ < 1 .
![Page 43: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/43.jpg)
§0 §1 §2 §3 §4 §5
Example. If L is of uniform finite type n along Σ, then L satisfies(LC) with σ =
nn + 1
.
Example. The vector field
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x
does not satisfy (LC) since
limt→0
t2 exp1− σ|t |
=∞ if σ < 1 .
![Page 44: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/44.jpg)
§0 §1 §2 §3 §4 §5
Example. If L is of uniform finite type n along Σ, then L satisfies(LC) with σ =
nn + 1
.
Example. The vector field
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x
does not satisfy (LC) since
limt→0
t2 exp1− σ|t |
=∞ if σ < 1 .
![Page 45: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/45.jpg)
§0 §1 §2 §3 §4 §5
Example. If L is of uniform finite type n along Σ, then L satisfies(LC) with σ =
nn + 1
.
Example. The vector field
L =∂
∂t− i(
1t2 exp
−1|t |
)∂
∂x
does not satisfy (LC) since
limt→0
t2 exp1− σ|t |
=∞ if σ < 1 .
![Page 46: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/46.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 47: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/47.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 48: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/48.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 49: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/49.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 50: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/50.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 51: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/51.jpg)
§0 §1 §2 §3 §4 §5
Example. If φ(x , t) is homogeneous of degree λ+ 1 andφt (x , t) > 0 for (x , t) 6= (0,0),then the vector field associatedwith Z = x + iφ(x , t) satisfies (LC) with σ = λ/λ+ 1.In polar coordinates
φ(r , θ) = rλ+1Q(θ) φt (r , θ) = rλP(θ)
with P(θ) > 0 ∀θ ∈ [0, 2π]. Thus
|φ(r , θ)|λ
λ+1 ≤ C|φt (r , θ)|
![Page 52: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/52.jpg)
§0 §1 §2 §3 §4 §5
Suppose that L is a vector field defined in an open set Ω′ ⊂ R2
s.t.L is hypocomplex;The characteristics Σ is 1-dimensional manifold;L satisfies (LC)
![Page 53: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/53.jpg)
§0 §1 §2 §3 §4 §5
Suppose that L is a vector field defined in an open set Ω′ ⊂ R2
s.t.L is hypocomplex;The characteristics Σ is 1-dimensional manifold;L satisfies (LC)
![Page 54: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/54.jpg)
§0 §1 §2 §3 §4 §5
Suppose that L is a vector field defined in an open set Ω′ ⊂ R2
s.t.L is hypocomplex;The characteristics Σ is 1-dimensional manifold;L satisfies (LC)
![Page 55: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/55.jpg)
§0 §1 §2 §3 §4 §5
Suppose that L is a vector field defined in an open set Ω′ ⊂ R2
s.t.L is hypocomplex;The characteristics Σ is 1-dimensional manifold;L satisfies (LC)
![Page 56: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/56.jpg)
§0 §1 §2 §3 §4 §5
Suppose that L is a vector field defined in an open set Ω′ ⊂ R2
s.t.L is hypocomplex;The characteristics Σ is 1-dimensional manifold;L satisfies (LC)
![Page 57: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/57.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 58: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/58.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 59: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/59.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 60: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/60.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 61: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/61.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 62: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/62.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 63: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/63.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 64: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/64.jpg)
§0 §1 §2 §3 §4 §5
Remark. L hypocomplex ⇒ L has a global first integral in Ω′.We can assume that there exist
Z : Ω′ −→ Z (Ω′) ⊂ C
a C1 homeomorphism, such that
LZ = 0 and dZ (p) 6= ∀p ∈ Ω′ .
We can assume that
L = Zx∂
∂y− Zy
∂
∂x.
Let Ω ⊂⊂ Ω′, Σ =∑N
j=1 Σj . For each j let σj be the exponent ofthe (LC) on Σj . Let σ = maxσj .
![Page 65: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/65.jpg)
§0 §1 §2 §3 §4 §5
Cauchy-Pompeiu operator
For f ∈ L1(Ω) define
TZ f (x , y) =1
2πi
∫Ω
f (ξ, η) dξdηZ (ξ, η)− Z (x , y)
.
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§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, then ∃M = M(p, σ,Ω) such that
|TZ f (x , y)| ≤ M ||f ||p , ∀(x , y) ∈ Ω .
If f ∈ L1(Ω), then TZ f (x , y) ∈ Lq(Ω) for any1 < q < 2− σ
σ + 1.
![Page 67: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/67.jpg)
§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, then ∃M = M(p, σ,Ω) such that
|TZ f (x , y)| ≤ M ||f ||p , ∀(x , y) ∈ Ω .
If f ∈ L1(Ω), then TZ f (x , y) ∈ Lq(Ω) for any1 < q < 2− σ
σ + 1.
![Page 68: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/68.jpg)
§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, then ∃M = M(p, σ,Ω) such that
|TZ f (x , y)| ≤ M ||f ||p , ∀(x , y) ∈ Ω .
If f ∈ L1(Ω), then TZ f (x , y) ∈ Lq(Ω) for any1 < q < 2− σ
σ + 1.
![Page 69: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/69.jpg)
§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, then ∃M = M(p, σ,Ω) such that
|TZ f (x , y)| ≤ M ||f ||p , ∀(x , y) ∈ Ω .
If f ∈ L1(Ω), then TZ f (x , y) ∈ Lq(Ω) for any1 < q < 2− σ
σ + 1.
![Page 70: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/70.jpg)
§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, then ∃M = M(p, σ,Ω) such that
|TZ f (x , y)| ≤ M ||f ||p , ∀(x , y) ∈ Ω .
If f ∈ L1(Ω), then TZ f (x , y) ∈ Lq(Ω) for any1 < q < 2− σ
σ + 1.
![Page 71: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/71.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
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§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 73: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/73.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 74: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/74.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 75: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/75.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 76: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/76.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 77: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/77.jpg)
§0 §1 §2 §3 §4 §5
Idea of the proof
Special case: Z = x + iy |y |σ
σ + 1If f ∈ Lp with p > 2 + σ
|TZ f (x , y)| ≤||f ||pπ
(∫Ω
dξ dη|Z (ξ, η)− Z (x , y)|q
) 1q
=||f ||pπ
J1q
with q =p
p − 1. Note that q < 2− τ , τ =
σ
σ + 1let
s = ξ = ReZ , t =η|η|σ
1 + σ= ImZ .
J = (1+σ)1
σ+1
∫Z (Ω)
ds dt|t |τ |ζ − z|q
≤ (1+σ)1
σ+1
∫D(z,R)
ds dt|t |τ |ζ − z|q
with ζ = s + it , z = Z (x , y) and R is the diameter of Z (Ω).
![Page 78: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/78.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 79: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/79.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 80: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/80.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 81: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/81.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 82: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/82.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 83: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/83.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
![Page 84: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/84.jpg)
§0 §1 §2 §3 §4 §5
Lemma ∫D(z,R)
ds dt|t |τ |ζ − z|q
≤ M(q)R2−q−τ
2− q − τ
This lemma together with the above estimate proves the specialcase. The general case can be brought into the special case bywriting
J =
∫Ω′
dξ dη|Z (ξ, η)− Z (x , y)|q
+N∑j
∫Vj
dξ dη|Z (ξ, η)− Z (x , y)|q
with Vj tubular neighborhood of Σj and Ω′ = Ω\⋃N
j=1 Vj . L iselliptic in Ω′ and L can be transformed into the special case ineach Vj with exponent σj .
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§0 §1 §2 §3 §4 §5
Let f ∈ L1(Ω). Let g ∈ Lp(Ω) with p > 2 + σ, then part (1)implies that
g1(x , y) =
∫Ω
|g(ξ, η)|dξ dη|Z (ξ, η)− Z (x , y)|
∈ L∞(Ω) and g1f ∈ L1(Ω) .
Then ∫Ω
fg1dxdy =
∫Ω|g(ξ, η)|
∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
dξdη
So∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
∈ Lq(Ω) and TZ f (x , y) ∈ Lq(Ω)
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§0 §1 §2 §3 §4 §5
Let f ∈ L1(Ω). Let g ∈ Lp(Ω) with p > 2 + σ, then part (1)implies that
g1(x , y) =
∫Ω
|g(ξ, η)|dξ dη|Z (ξ, η)− Z (x , y)|
∈ L∞(Ω) and g1f ∈ L1(Ω) .
Then ∫Ω
fg1dxdy =
∫Ω|g(ξ, η)|
∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
dξdη
So∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
∈ Lq(Ω) and TZ f (x , y) ∈ Lq(Ω)
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§0 §1 §2 §3 §4 §5
Let f ∈ L1(Ω). Let g ∈ Lp(Ω) with p > 2 + σ, then part (1)implies that
g1(x , y) =
∫Ω
|g(ξ, η)|dξ dη|Z (ξ, η)− Z (x , y)|
∈ L∞(Ω) and g1f ∈ L1(Ω) .
Then ∫Ω
fg1dxdy =
∫Ω|g(ξ, η)|
∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
dξdη
So∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
∈ Lq(Ω) and TZ f (x , y) ∈ Lq(Ω)
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§0 §1 §2 §3 §4 §5
Let f ∈ L1(Ω). Let g ∈ Lp(Ω) with p > 2 + σ, then part (1)implies that
g1(x , y) =
∫Ω
|g(ξ, η)|dξ dη|Z (ξ, η)− Z (x , y)|
∈ L∞(Ω) and g1f ∈ L1(Ω) .
Then ∫Ω
fg1dxdy =
∫Ω|g(ξ, η)|
∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
dξdη
So∫Ω
|f (x , y)| dxdy|Z (x , y)− Z (ξ, η)|
∈ Lq(Ω) and TZ f (x , y) ∈ Lq(Ω)
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§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ L1(Ω), then LTZ f (x , y) = f
The proof is consequence of
Proposition
If w ∈ C0(Ω) ∩ C1(Ω), then
w(x , y) =1
2πi
∫∂Ω
w(ξ, η)
Z (ξ, η)− Z (x , y)dZ (ξ, η)
− 1π
∫Ω
Lw(ξ, η)
Z (ξ, η)− Z (x , y)dξdη .
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§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ L1(Ω), then LTZ f (x , y) = f
The proof is consequence of
Proposition
If w ∈ C0(Ω) ∩ C1(Ω), then
w(x , y) =1
2πi
∫∂Ω
w(ξ, η)
Z (ξ, η)− Z (x , y)dZ (ξ, η)
− 1π
∫Ω
Lw(ξ, η)
Z (ξ, η)− Z (x , y)dξdη .
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§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ L1(Ω), then LTZ f (x , y) = f
The proof is consequence of
Proposition
If w ∈ C0(Ω) ∩ C1(Ω), then
w(x , y) =1
2πi
∫∂Ω
w(ξ, η)
Z (ξ, η)− Z (x , y)dZ (ξ, η)
− 1π
∫Ω
Lw(ξ, η)
Z (ξ, η)− Z (x , y)dξdη .
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§0 §1 §2 §3 §4 §5
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ L1(Ω), then LTZ f (x , y) = f
The proof is consequence of
Proposition
If w ∈ C0(Ω) ∩ C1(Ω), then
w(x , y) =1
2πi
∫∂Ω
w(ξ, η)
Z (ξ, η)− Z (x , y)dZ (ξ, η)
− 1π
∫Ω
Lw(ξ, η)
Z (ξ, η)− Z (x , y)dξdη .
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Let φ ∈ D(Ω).
< LTZ f (x , y), φ > = − < TZ f (x , y),Lφ >
=
∫Ω
f (ξ, η)
(−1π
∫Ω
Lφ(x , y)
Z (x , y)− Z (ξ, η)dxdy
)dξdη
=< f , φ > .
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Let φ ∈ D(Ω).
< LTZ f (x , y), φ > = − < TZ f (x , y),Lφ >
=
∫Ω
f (ξ, η)
(−1π
∫Ω
Lφ(x , y)
Z (x , y)− Z (ξ, η)dxdy
)dξdη
=< f , φ > .
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Remark. f ∈ Lp with p > 2 + σ is optimal for obtaining boundedsolutions.For the standard vector field
∂
∂y− i |y |σ ∂
∂xand
f (x , y) =−i |y |σ
Z (x , y) ln |Z (x , y)|∈ Lp(R2) for any p < 2 + σ
but f /∈ Lp′with p′ > 2 + σ. The function
u(x , y) = ln |ln Z (x , y)| /∈ L∞ and satisfies Lu = f . EquationLu = f has no bounded solutions.
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§0 §1 §2 §3 §4 §5
Hölder continuity
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, and Lu = f , then u ∈ Cα(Ω) with
α =2− q − τ
q
The proof uses the lemma
Lemma ([C. Campana, P. Dattori, A.M.])For z1 6= z0 and τ < 1, we have∫
D(0,R)
dξ dη|η|τ |ζ − z1|q |ζ − z0|q
≤ C(p, τ) |z1 − z0|2−2q−2τ
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§0 §1 §2 §3 §4 §5
Hölder continuity
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, and Lu = f , then u ∈ Cα(Ω) with
α =2− q − τ
q
The proof uses the lemma
Lemma ([C. Campana, P. Dattori, A.M.])For z1 6= z0 and τ < 1, we have∫
D(0,R)
dξ dη|η|τ |ζ − z1|q |ζ − z0|q
≤ C(p, τ) |z1 − z0|2−2q−2τ
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§0 §1 §2 §3 §4 §5
Hölder continuity
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, and Lu = f , then u ∈ Cα(Ω) with
α =2− q − τ
q
The proof uses the lemma
Lemma ([C. Campana, P. Dattori, A.M.])For z1 6= z0 and τ < 1, we have∫
D(0,R)
dξ dη|η|τ |ζ − z1|q |ζ − z0|q
≤ C(p, τ) |z1 − z0|2−2q−2τ
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§0 §1 §2 §3 §4 §5
Hölder continuity
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, and Lu = f , then u ∈ Cα(Ω) with
α =2− q − τ
q
The proof uses the lemma
Lemma ([C. Campana, P. Dattori, A.M.])For z1 6= z0 and τ < 1, we have∫
D(0,R)
dξ dη|η|τ |ζ − z1|q |ζ − z0|q
≤ C(p, τ) |z1 − z0|2−2q−2τ
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§0 §1 §2 §3 §4 §5
Hölder continuity
Theorem ([C. Campana, P. Dattori, A.M.])
If f ∈ Lp(Ω) with p > 2 + σ, and Lu = f , then u ∈ Cα(Ω) with
α =2− q − τ
q
The proof uses the lemma
Lemma ([C. Campana, P. Dattori, A.M.])For z1 6= z0 and τ < 1, we have∫
D(0,R)
dξ dη|η|τ |ζ − z1|q |ζ − z0|q
≤ C(p, τ) |z1 − z0|2−2q−2τ
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
Proof of Theorem
Set z1 = Z (x1, y1) and z0 = Z (x0, y0).
|TZ f (x1, y1)− TZ f (x0, y0)| ≤ |z1 − z0|π
∫Ω
|f (ξ, η)|dξdη|Z (ξ, η)− z1| |Z (ξ, η)− z0|
≤||f ||pπ|z1 − z0|H
1q
withH =
∫Ω
dξdη|Z (ξ, η)− z1|q |Z (ξ, η)− z0|q
Case Z (x , y) = x +y |y |σ
σ + 1. Let R > 0 s.t. Z (Ω) ⊂ D(0,R) and
s = ξ, t =y |y |σ
σ + 1It follows from the lemma that
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§0 §1 §2 §3 §4 §5
H ≤ 1(1 + σ)τ
∫D(0,R)
ds dt|t |τ |ζ − z1|q |ζ − z0|q
≤ C(q, τ)|z1 − z0|2−2q−τ
and
|TZ f (x1, y1)− TZ f (x0, y0)| ≤||f ||pπ|z1−z0|H
1q ≤ C(p, τ)|z1−z0|α
with α =2− q − τ
q.
The general case can be reduced to this special case as wasdone previously.
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§0 §1 §2 §3 §4 §5
H ≤ 1(1 + σ)τ
∫D(0,R)
ds dt|t |τ |ζ − z1|q |ζ − z0|q
≤ C(q, τ)|z1 − z0|2−2q−τ
and
|TZ f (x1, y1)− TZ f (x0, y0)| ≤||f ||pπ|z1−z0|H
1q ≤ C(p, τ)|z1−z0|α
with α =2− q − τ
q.
The general case can be reduced to this special case as wasdone previously.
![Page 115: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/115.jpg)
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H ≤ 1(1 + σ)τ
∫D(0,R)
ds dt|t |τ |ζ − z1|q |ζ − z0|q
≤ C(q, τ)|z1 − z0|2−2q−τ
and
|TZ f (x1, y1)− TZ f (x0, y0)| ≤||f ||pπ|z1−z0|H
1q ≤ C(p, τ)|z1−z0|α
with α =2− q − τ
q.
The general case can be reduced to this special case as wasdone previously.
![Page 116: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/116.jpg)
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H ≤ 1(1 + σ)τ
∫D(0,R)
ds dt|t |τ |ζ − z1|q |ζ − z0|q
≤ C(q, τ)|z1 − z0|2−2q−τ
and
|TZ f (x1, y1)− TZ f (x0, y0)| ≤||f ||pπ|z1−z0|H
1q ≤ C(p, τ)|z1−z0|α
with α =2− q − τ
q.
The general case can be reduced to this special case as wasdone previously.
![Page 117: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/117.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 118: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/118.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 119: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/119.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 120: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/120.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 121: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/121.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 122: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/122.jpg)
§0 §1 §2 §3 §4 §5
Semilinear Equation
The regularity of solutions of uy = f (x , y ,u,ux ) was studied bymany authors using the FBI transform. Including: [Adwan,Berhanu](2012); [Asano] (1995);[Baouendi-Goulaouic-Treves](1985); [Berhanu] (2009), [Lerner,Morimoto, Xu] (2008). The last chapter of Treves book"Hypo-analytic Structures" deals with nonlinear structures.However, in all these works, the function f (x , y , ζ0, ζ1) isassumed to be holomorphic in (ζ0, ζ1).A paper by Hounie and Santiago (1996) considers the equationLu = f (x ,u) with L satisfies (P). They prove in particularexistence of Lp solutions if f ∈ Lp.
![Page 123: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/123.jpg)
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Let F (x , y , ζ) be a function defined on Ω× C such thatFor every ζ ∈ C, F (., ζ) ∈ Lp(Ω) with p > 2 + σ;There exists ψ(x , y) ∈ Lp(Ω) and β ∈ (0, 1] s.t.
|F (x , y , ζ1)− F (x , y , ζ0)| ≤ ψ(x , y) |ζ1 − ζ0|β
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Let F (x , y , ζ) be a function defined on Ω× C such thatFor every ζ ∈ C, F (., ζ) ∈ Lp(Ω) with p > 2 + σ;There exists ψ(x , y) ∈ Lp(Ω) and β ∈ (0, 1] s.t.
|F (x , y , ζ1)− F (x , y , ζ0)| ≤ ψ(x , y) |ζ1 − ζ0|β
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Let F (x , y , ζ) be a function defined on Ω× C such thatFor every ζ ∈ C, F (., ζ) ∈ Lp(Ω) with p > 2 + σ;There exists ψ(x , y) ∈ Lp(Ω) and β ∈ (0, 1] s.t.
|F (x , y , ζ1)− F (x , y , ζ0)| ≤ ψ(x , y) |ζ1 − ζ0|β
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Let F (x , y , ζ) be a function defined on Ω× C such thatFor every ζ ∈ C, F (., ζ) ∈ Lp(Ω) with p > 2 + σ;There exists ψ(x , y) ∈ Lp(Ω) and β ∈ (0, 1] s.t.
|F (x , y , ζ1)− F (x , y , ζ0)| ≤ ψ(x , y) |ζ1 − ζ0|β
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Semilinear equation
Theorem ([C. Campana, P. Dattori, A.M.])
Let F (x , y ,u) be as above, α =2− q − τ
q, τ =
σ
σ + 1. Then
If β < 1, equation Lu = F (x , y ,u) has a solution in Cα(Ω);If β = 1, then for every (x , y) ∈ Ω, there is an openneighborhood U ⊂ Ω such that equation Lu = F (x , y ,u)has a solution u ∈ Cα(U) .
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§0 §1 §2 §3 §4 §5
Semilinear equation
Theorem ([C. Campana, P. Dattori, A.M.])
Let F (x , y ,u) be as above, α =2− q − τ
q, τ =
σ
σ + 1. Then
If β < 1, equation Lu = F (x , y ,u) has a solution in Cα(Ω);If β = 1, then for every (x , y) ∈ Ω, there is an openneighborhood U ⊂ Ω such that equation Lu = F (x , y ,u)has a solution u ∈ Cα(U) .
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§0 §1 §2 §3 §4 §5
Semilinear equation
Theorem ([C. Campana, P. Dattori, A.M.])
Let F (x , y ,u) be as above, α =2− q − τ
q, τ =
σ
σ + 1. Then
If β < 1, equation Lu = F (x , y ,u) has a solution in Cα(Ω);If β = 1, then for every (x , y) ∈ Ω, there is an openneighborhood U ⊂ Ω such that equation Lu = F (x , y ,u)has a solution u ∈ Cα(U) .
![Page 130: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/130.jpg)
§0 §1 §2 §3 §4 §5
Semilinear equation
Theorem ([C. Campana, P. Dattori, A.M.])
Let F (x , y ,u) be as above, α =2− q − τ
q, τ =
σ
σ + 1. Then
If β < 1, equation Lu = F (x , y ,u) has a solution in Cα(Ω);If β = 1, then for every (x , y) ∈ Ω, there is an openneighborhood U ⊂ Ω such that equation Lu = F (x , y ,u)has a solution u ∈ Cα(U) .
![Page 131: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/131.jpg)
§0 §1 §2 §3 §4 §5
Semilinear equation
Theorem ([C. Campana, P. Dattori, A.M.])
Let F (x , y ,u) be as above, α =2− q − τ
q, τ =
σ
σ + 1. Then
If β < 1, equation Lu = F (x , y ,u) has a solution in Cα(Ω);If β = 1, then for every (x , y) ∈ Ω, there is an openneighborhood U ⊂ Ω such that equation Lu = F (x , y ,u)has a solution u ∈ Cα(U) .
![Page 132: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/132.jpg)
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
![Page 135: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/135.jpg)
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
![Page 137: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/137.jpg)
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Proof
For N > 0, let
CN(Ω) = u ∈ C(Ω); ||u||∞ ≤ N
Let M(p, σ,Ω) found earlier such that
||TZ f ||∞ ≤ M(p, σ,Ω)||f ||p ∀f ∈ Lp(Ω), p > 2 + σ
Case β < 1. Let N be large enough so that
M(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
)≤ N .
![Page 138: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/138.jpg)
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Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
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Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
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Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
![Page 141: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/141.jpg)
§0 §1 §2 §3 §4 §5
Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
![Page 142: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/142.jpg)
§0 §1 §2 §3 §4 §5
Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
![Page 143: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/143.jpg)
§0 §1 §2 §3 §4 §5
Let P : CN(Ω) −→ CN(Ω):
Pu(x , y) = TZ F (x , y ,u(x , y)) .
P is well defined since
|Pu(x , y)| ≤ M(p, σ,Ω)||F (x , y ,u)||p≤ M(p, σ,Ω) (||F (x , y ,u)− F (x , y ,0)||p + ||F (x , y ,0)||p)
≤ M(p, σ,Ω)(||ψ||pNβ + ||F (x , y ,0)||p
)≤ N
Also the continuity of Pu follows from that of the integraloperator TZ F :
|Pu(m1)− Pu(m0)| ≤ C(p, σ,Ω)||F (.,u)||p |Z (m1)− Z (m0)|α
≤ C(p, σ,Ω)N |Z (m1)− Z (m0)|α
![Page 144: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/144.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 145: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/145.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 146: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/146.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 147: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/147.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 148: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/148.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 149: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/149.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 150: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/150.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)
![Page 151: I. Hölder continuous solutions of a class of planar …faculty.fiu.edu/~meziani/Serra-Negra 1.pdfI. Hölder continuous solutions of a class of planar vector fields Hamid Meziani](https://reader035.vdocuments.site/reader035/viewer/2022062414/5edc9352ad6a402d66674c08/html5/thumbnails/151.jpg)
§0 §1 §2 §3 §4 §5
Let C = C(p, σ,Ω)(||ψ||pNβ + ||F (.,0)||p
). and
ΛN,C = u ∈ CN(Ω) : |u(m1)− u(m0)| ≤ C |Z (m1)− Z (m0)|α .
ΛN,C is a convex subset of CN(Ω) and compact (Ascoli-Arzela).We have P(CN(Ω)) ⊂ ΛN,C and
|Pu(m)− Pv(m)| = |TZ F (m,u)− TZ F (m, v)|≤ M(p, σ,Ω)||F (.,u)− F (., v)||p≤ M(p, σ,Ω)||ψ||p||u − v ||β∞
P : ΛN,C −→ ΛN,C is continuous. By Schauder fixed pointtheorem, there is u ∈ ΛN,C satisfying u = Pu .ThusLu = LTZ F (x , y ,u) = F (x , y ,u)