Post on 17-Jan-2016
Center for Theoretical Physics University of Provence
Marseille
Christian Marinoni
Testing Cosmological Models with High Redshift Galaxies
Gravity Gravity
Field equationsField equations Metric Metric
RW line elementRW line element
TG ])([ 22222 dSdadtds k
Nature of Dark Energy
?New source?
New gravitational physics
?
Inhomogeneus universe
• Testing Gravity at z=1
- with 2nd order statistics :
- redshift evolution of the linear growth factor of density fluctuations
- with 3rd order statistics :
- Redshift Evolution of the skewness of the galaxy density fluctuations
• Testing cosmological models
- The cosmological lensing of galaxy diameters
Outline
δ Field
2DFGRS/SDSS stop here
Marinoni et al. 2008 A&A in press (arXiv 0802.1838)
Gaussian Filter R=2Mpc)
2dFGRS (Colless et al. 00)
<Z>=0.1120,000 galaxiesf=0.5±0.1σ=390±50 km/s
(Peacock et al. 2001, Nature)
Testing gravity with second order statistics :
VVDS LeFevre et al. 05
<Z>=0.75~6,000 galaxiesf=0.9±0.4σ=400±50 km/s
(Guzzo et al. 2008 Nature 2008)
ad
Ddtf
ln
ln)(
Constraining the physics behind acceleration
In principle, f can reveal the physical origin of the acceleration
Predicted constraintsfrom SPACEmissison
)()( ttf m
In linear theory
Testing gravity with third order statistics : Skewness
Galaxy fluctuations were significantly non Gaussian even at early times
Conclusion: 3rd order GIP predictions consistent with data only if, even locally, biasing is non-linear at the level measured by VVDS See also Feldman et al. 2001
04.019.01
2 b
b k
kkg k
b !
Biasing at high z cannot be described in terms of a single constant
Marinoni et al. 2005, A&A, 442, 801
R=10h-1MpcMarinoni et al. 2008 A&A in press (arXiv:0802.1838)
Verde et al. 01
Croton et al. 2005
Juszkievicz et al. 1993 Hivon et al. 1995
315.17
2.35)(3 nzS
1
23
11,3 3)(
b
bSbzS g
Mass skewness
Galaxy skewness
D
Angular Diameter Test
Metric constraints using the kinematics of high redshift disc galaxiesMarinoni, Saintonge, Giovanelli et al. 2007 A&A , 478, 41Saintonge, Master, Marinoni et al. 2007 A&A, 478, 57Marinoni, Saintonge Contini et al. 2007 A&A , 478, 71
),(
)()(
zd
zDz
A
Theory predicts :
Standard Rod Selection
Saintonge et al. 2008 A&A,478, 57
Observationally Confirmed
%20rr
VD
The angular diameter test with high-velocity rotatorsThe angular diameter test with high-velocity rotators
Predictions for V>200km/s (big) galaxies
zCOSMOS (1 deg2): ~ 1300 rotators and (σD/D)int=20%
full VVDS (16 deg2): ~ 20 000 rotators and (σD/D)int=20%
Many cosmological tests make use of only two functions of redshiftThe angular diameter distance dA(z) and the radial comoving distance r(z)
Violation of consistency might indicate Non-RW geometry
Tests of the Cosmological Principle
These two quantities are not independent, as they are related by the cosmic consistency relation (e.g. Stebbins 2007)
)( 1
)( zrKSK
zd kA where
1,1,0for )sinh( ),sin( ,][ kxxxxSk
0
2/10 |1|
H
cK Spatial curvature
The consistency tests with high velocity rotatorsThe consistency tests with high velocity rotators
~30 disc galaxies hosting a supernovae in the zCOSMOS field
Sinfoni+
HSTVIMOS+Cosmos
Z=0.5
Z=0.9
Implementation Strategy:
HST/Cosmos imaging survey:
HR Spectroscopy (VIMOS)
VLT HST
Observations underway with VIMOS at VLT in the COSMOS field (accepted ESO proposal, P.I. L. Tresse)
Very Quick (…but large) Survey!!
~1300 rotators down to Iab 22.5 in only 30h
Retarget in High spectroscopic resolution zCOSMOS discs with known emission lines and redshift
Preliminary Preliminary datadata
1 ,75.0 ,25.0 X -wm
Comparison with thepredicted angular evolution in the standard ΛCDM background
0<v(km/s)<100 100<v(km/s)<200
Standard Rod Selection
Best fitting model
ΛCDM
Cosmological Constraints from Preliminary data
By imposing that luminosity emitted per unit mass was higher in the past we can exclude :* SCDM (EdS) at 3σ* OCDM (ΩM=ΩT=0.3) at more than 1σ with 30 rotators at <z>=1 only !!!
Observational constraints: 1) luminosity emitted per unit mass was higher In the past.2) SB evolution as inferred from data
Which is the region of the cosmological parameter spacewhich is compatible with theseexternal constraints?
Conclusions
- semi-linear GIP predictions for skewness evolution are consistent with data in the range 0<z<1.5 only if biasing is non-linear at the level measured by VVDS. If local (z=0) bias is linear GIP ruled out at 5 sigma!
-Evolution of the linear growth factor gives insigths into the nature of DE. Still large errorbars affects VVDS measurements. Need larger deep surveys (e.g. SPACE)
- Observations underway in the COSMOS/HST field to collect a large sample of velocity selected standard rods (VIMOS @ VLT)and test cosmology with the angular diameter test of cosmology
EVOLUTIONEVOLUTION
According to theory (analytic models and simulations) big baryonic discs already completed their evolution before z=1Chiappini, Matteucci & Gratton 1997Boissier & Prantzos 2001Bowens & Silk 2001Ferguson & Clarke 2003Somerville et al. 2007
Theory predicts that the rotation velocity at a given stellar mass is only about 10% larger at z~1 than at the present day
Excluded Region
`matter density Test’
Structural Parameters Evolution
0<V(km/s)<100 100<V(km/s)<200
Theoretical Interpretation: Which is the physical mechanism governing biasing evolution?
Gravity(Dekel and Rees 88Tegmark & Peebles 98)
Merging(Mo & White 96Matarrese et al. 97)
IstantaneousStar Formation(Blanton et al 02)
2
222 )(
b
bL
Field Reconstruction Technique
)( gg
Z=0.7-1.1 Z=1.1-1.5
g(g )dg ()d
Extraction of Biasing
G4H2 Linear ApproximationNewtonian RegimePressureless Matter fluidAdiabatic perturbation
Linear Growth of CDM structures
)()(),( tDxtx i It exists an unstable growing solution
1) TESTING GRAVITY (GR)
Fundamental variable describing the LSS structure
22 )( t223
3 /)( c
tS
Statistical Strategy : Analyze fluctuations moments
dtPR )()]([
Evolution of low order moments
Marinoni et al. A&A 2005
Fluctuations in the visible sector have frozen over ~2/3 of the history of the universe
The Young universe was as much inhomogeneous as it is nowdays
Second Moment
Galaxy distribution was significantly non Gaussian even at early times
Third Moment
Marinoni et al. A&A 2007
Volume-limited sample M<-20+5log h
The outstanding problem : Dark EnergyThe outstanding problem : Dark Energy
- The Fine Tuning Problem Particle physics theory currently provides no
understanding of why the vacuum energy
density is so small:
- The Cosmic Coincidence ProblemTheory provides no understanding of why the Dark Energy
density is just now comparable to the matter density.
- Nature : What is it?Is dark energy a scalar field ? a breakdown of General Relativity
on large scales?
DarkWhat do we know ? Smooth on cluster scales Accelerating the Universe
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