primordial neutrinos and cosmological perturbation in the interacting dark-energy model: cmb and lss...
TRANSCRIPT
Primordial Neutrinos and Cosmological Perturbation in the Interacting Dark-Energy Model: CMB and LSS
Yong-Yeon Keum
National Taiwan University
SDSS-KSG Winter Workshop February 20-22, 2007
From CMB + SN1a + structure formation
•Starlight from Galaxies•Stuff we are made of!!
•Light elements from early hot universe• Low CMB temperature fluctuations
•Accelerated expansion of the universe (High redshift SN)•Structure formation scenario compatible with observations
•Rotation of galaxies•Speeding galaxies in clusters•Gravitational lensing•Hot gas in clusters
Matter budget of the cosmos
Fig:NASA/WMAP science team
What we know so farWhat we know so farFrom SNIa and CMB radiation observations, Our universe is almost flat, now accelerating. The dominance of a dark energy component
with negative pressure in the present era is responsible for the universe’s accelerated
expansion.
NASA/WMAP science team
Total energy density
Baryonic matter density
Dawn of Precision cosmology !!
Dark energy density
Good old Cosmology, … New trend !
Candidates of Dark EnergyCandidates of Dark Energy
(A) Cosmological Constant(B) Dynamical Cosmological constant
(Time-dependent; Quintessence ) - quintessence: potential term + canonical kinetic
term
- K-essence: non-canonical kinetic term
- phantom - quintom -Tachyon field
(C) Modified Gravity (Modified friedman eq.)
Classification of Dark-Energy Classification of Dark-Energy ModelsModels
• We redefine two parameter space of observables: / l n /d d a d Hdt
<w<-0.82(2
P
Primordial NeutrinosPrimordial Neutrinos
The connection between cosmological observations and neutrino physics is one of the interesting and hot topic in astro-particle physics.
Neutrino decouple from thermal contact in the early universe at the temperature of order 1 MeV which coincides with the temperature where light element synthesis occurs.
Precision observations of the cosmic microwave background and large scale structure of galaxies can be used to prove neutrino mass with greater precision than current laboratory experiments.
Interacting Dark-Energy modelsInteracting Dark-Energy models
o o interacting between cold dark-matter and dark-energy: interacting between cold dark-matter and dark-energy: (Farrar and Peebles, 2004)(Farrar and Peebles, 2004)
o o interacting between photon and dark-energy: interacting between photon and dark-energy: (Feng et al., 2006; Liu et al., 2006)(Feng et al., 2006; Liu et al., 2006)
o o interacting betweeninteracting between neutrinos and dark-energy:neutrinos and dark-energy:(Fardon et al. 2004, Zhang et al. 2005, yyk and Ichiki, 2006)(Fardon et al. 2004, Zhang et al. 2005, yyk and Ichiki, 2006)
Neutrino Model of Dark EnergyNeutrino Model of Dark Energy
Cosmological constant:
What physics is associated with this small energy scale ?? It is clearly a challenge to understand dynamically how the
small energy scale associated with dark-energy(DE) density aries and how it is connected to particle physics.
33 2 2 40
0
4 4 )
( ) 1
(1.5 0.1) 10 , )
N DE N DE
DE DE
DE P o
G G p p
p
Since H x eV M H eV
E eV
10
Questions :Questions :
Why does the mass scale of neutrinos so small ?
about 10-3 eV ~ Eo: accidental or not ?
If not, are there any relation between Neutrinos and Dark Energy ?
33 210 /m eV m M
2 3 41/ 10 10cL l H H l m M eV
M
Interacting dark energy modelInteracting dark energy model
Example At low energy,
The condition of minimization of Vtot determines the physical neutrino mass.
nv mvScalar potential
in vacuum
Mass Varying Neutrino ModelMass Varying Neutrino Model
Fardon,Kaplan,Nelson,Weiner: PRL93, 2004Fardon,Kaplan,Nelson,Weiner: PRL93, 2004
Fardon, Nelson and Weiner suggested that tracks the energy density in neutrinos
The energy density in the dark sector has two-components:
The neutrinos and the dark-energy are coupled because it is assumed that dark energy density is a function of the mass of the neutrinos:
DE
( )m m n
dark DE
( )DE DE n
Since in the present epoch, neutrinos are non-relativistic (NR),
Assuming dark-energy density is stationary w.r.t. variations in the neutrino mass,
Defining
( )dark DEm n m n m
( )0
3 ( )
dark DE mn
m m
H p
,
1
dark
dark
dark dark DE DE
dark DE
p
p p p
m n m n
m n
Lessons-I:Lessons-I:
Wanted neutrinos to probe DE, but actually are DE.
flat scalar potential (log good) choice,
mv < few eV.
Neutrino mass scales as mv ~ 1/nv:
- lighter in a early universe, heavier now - lighter in clustered region, heavier in FRW
region - lighter in supernovae An example of the inhomogenous matter
distributions:
Lessons-IILessons-II
Couplings of ordinary matter to such scalars strongly constrained – must be weaker than Planck: 1/Mpl
2i j
[ + ] : f or or di nar y mat t er
[ + ] : f or neut r i no
ii j jp
i jp
f H ffM
fl H Hl ff
M M M
R.D. Peccei; PRD71 (2005)
With exponential type potential
bb
The FNW scenario is only consistent, if there is no kinetic contributions (K=0) and
the dark-energy is a pure running cosmological constant !!
Cosmological Perturbation in the Interacting Dark-Energy Model
CMB and Large Scale Structures
K. Ichiki and YYK
Background Equations:Background Equations:
We consider the linear perturbation in the synchronous Gauge and the linear elements:
Perturbation Equations:
Varying Neutrino MassVarying Neutrino Mass
eV eV
With full consideration of Kinetic term
V( )=Vo exp[- ]
W_effW_eff
eV eV
eV
eV
Power-spectrum (LSS)Power-spectrum (LSS)
eV eV
eeInverse Power law potential
Neutrino mass vs zNeutrino mass vs z
W_eff(z)W_eff(z)
CMB spectrumCMB spectrum
Power spectrum with Power spectrum with
Constraints from ObservationsConstraints from Observations
WMAP3 data on Ho vs WMAP3 data on Ho vs
ConclusionsConclusions
Neutrinos are the best probe of SM into DE sector
Possible origin for accelerating universe
Motivates consideration of new matter effects to be seen in oscillations: - LSND interpretation (if MinibooNe has a signal) - Matter/air analyses - Solar MaVaN oscillation Effects - Time delay in the gamma ray bursts.
Thanks Thanks For For your your attention!attention!