acceleration of universe background level evolution of expansion: h(a), w(a) degeneracy: de &...
TRANSCRIPT
Acceleration of Universe Background level
Evolution of expansion: H(a), w(a) degeneracy: DE & MG
Perturbation level Evolution of inhomogeneity: G(a), G(a, k),
Phi, Psi…
Smoothing energy component or modified gravity? Scalar field F(R), DGP, TeVeS,
Growth of LSS
Expansion: H(a) consistency relation: H_growth vs.
H_expansion Metric perturbation:
Modified Gravity H(a) Modified Poisson equation.
G_eff
Parametrization Growth index (scale-independent)
~
1
~
~ ~
( ) gravity:
DGP gravity: 1
TeVeS: ( ,other fields)
R
Geff f
eff
eff eff uv
f R G
G
G G g
convergence power (cross) spectrum
rich information (power spectrum, cross-spectrum)
photo-z error
standard ruler
Spectroscopic survey δ field
Growth factor G(z) v field
(redshift distortion) β~ dlnG/dlna
2009 XuGuangqi-Galieo conference7
A sensitive measure of gravity
Guzzo et al. 2008
Acquaviva et al. 2008
Spectroscopic redshift surveys•Measure beta from the anisotropy•Measure galaxy bias•Obtain f
Current measurements
Standard Candle
variation of SN peak L (after the standardization)
photo-z error (without spectrum)
z-dependent peak L (e.g. SN evolution, extinction)
mass of clusters are not measured directly (except for WL)
complex baryon physics (hydrodynamics, galaxies formation)
SZ flux decrement, X-ray temperature, gas mass
mass selection function
number distribution
angular density
BAO Spectroscopic survey
Photometric survey
Supernovae 200 SNIa/year/deg^2 available for z<1.2 (limit for ground experiment)
SN1: 50 /y/deg^2 SN2: 100 /y/deg^2
photo-z error N_c: # of spectra for calibration
Systematics (Nuisance parameters):
absolute magnitude
quadratic offset
Weak Lensing (same as Sun lei & Zhao Gongbo)
Clusters Count
Genus
Gaussian fluctuation: 3D (δ)
2D (weak lensing, κ)
Resistant against: Bias, redshift distortion, weak nonliearity.
In GR Invariant amplitude. Standard ruler
In MG Introduce new scale-dependence time-varying Complementary to growth rate of matter
fluctuation. Sensitive to scale-dependent modification at sub-horizon
scale.
Fisher calculation:
Testing the (generalized) Poisson Equation
)d 2s= ( - )W( ,
2 ( ) 8 G
2009 XuGuangqi-Galieo conference 19
=
Gravitational lensing
v H
f
fH
/
from peculiar velocity
?
Galaxy redshifts to recover redshift information (2D ->3D)
2009 XuGuangqi-Galieo conference 20
LCDMf(R)DGPMOND/TeVeS
ZPJ et al. 2007
• EG will be measured to 1% level accuracy within two decades
• Promising to detect one percent level deviation from general relativity+canonical dark energy model (if systematics can be controlled)!
2009 XuGuangqi-Galieo conference21
ZPJ et al. 2008
•eta can be measured to 10% accuracy.
•Errors in eta is larger than errors in E_G•Even so, eta can have stronger discriminating power, in some cases.
•η of DGP differs significantly from that of LCDM. (EG of DGP is very close to that of LCDM.)
•eta and E_G are complementary
•DGP with high Omega_m
SKA forecast
DGP
MONDTeVeS
dark energy with anisotropic stress
One can further construct an estimator ofLensing: Φ-Ψ; Peculiar velocity: Ψ
Thanks