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

{

12010Theode

Obsde