1. How Different was the Universe at z=1? Centre de Physique Théorique, Marseille Université de Provence Christian Marinoni

2. Observations - Constrain baryonic physics - Disentangle Nature and Nurture scenarios Dark Matter Local properties: Constraining galaxy structural parameters at z=1 t Evolution is Known Simply gravitational! Not Dark Matter Evolution ? Complex physics! Sondages spectro-photometriques de l’univers profond (VVDS,zCOSMOS)

3. Global Properties : Constraining Cosmological parameters at z=1 - Galaxies (WL, Power spectrum, Age test…) - Clusters of galaxies (SZ+X, Abundance, Baryon fraction…) Need for a purely geometrical approach with self consistent treatment of evolution Diagnostic that takes into account consistently source evolution and background cosmology Pro: - Lots of objects - Different degeneracies w/r to SN, CMB Con: - None Independent from assumptions on physical models, Galaxy-DM bias, simulation prescriptions - Source evolution

4. A new implementation strategy for the Angular diameter test using high z galaxies Preliminary Results on Cosmology and Evolution of Galaxy Structural Parameters Outline Marinoni, Saintonge, Le Fevre, et al. 2006 A&A submitted Saintonge, Masters, Marinoni, et al. 2006 A&A submitted Marinoni, Saintonge, Contini et al. 2006 A&A submitted

5. Metric constraints using the kinematics of high redshift disc galaxies  (D,z,  ) Method: V L=F(D) Standard Rod Selection D Direct geometrical test of cosmology Independent of physics, and simulations (Tolman test)

6. Sample: Deep “cone” (2h Field: first-epoch data) ~7000 galaxies with secure redshifts, I AB  24 Coverage: 0.7x0.7 sq. deg (40x40 Mpc at z=1.5) Volume sampled: 2x10 6 Mpc 3 (~CfA2) (1/16th of final goal) 4300 Mpc Mean inter-galaxy separation at z=0.8 ~4.3 Mpc (~2dF at z=0.1) Sampling rate: 1 over 3 galaxies down to I=24 z=0 z=1.5

7. Standard Rod selection Z=0.5 Z=0.9 Implementation Strategy: Cosmos : major space imaging survey: 590 orbits of ACS/HST HR VVDS Spectroscopy 2 VLTHST 0<v(km/s)<100 0<v(km/s)<200

8. The angular diameter test : Evolutionary effects - Modelling different redshift evolutions for the standard rod (galaxy discs) Consider 3 different evolutionary scenarios - Late epoch evolution - Linear evolution - Early epoch evolution

9. Evolution Effects in the angular diameter test - Is there a feature that may be used to discriminate the presence of evolution? - Is there a particular evolutionary scenario for which the inferred values of Ω Λ and w are minimally biased? Yes! Linear e(z) Yes

10. Evolution Effects: Bias in the Ω Λ – w plane - Predictions using a simulated sample of 1000 standard rods - No flat prior Fiducial : NO Evolution Retrieved 40% linear evolution in discs at z=1 Fiducial model still within 1σ also when strong linear evolution is present

11. Cosmology - Evolution Diagram at z=1 Only imposing ΔM(z)<0 i.e. that objects were brighter in the past Is it possible to infer cosmological information without a priori knowing e(z) ? Yes! One may derive a mapping between cosmological space and evolution space V~150km/s sample

12. Evolution of Galaxy Structural Parameters D(z), L(z), μ(z) up to z=1 Small Mass Galaxies V~70 km/s High Mass Galaxies V~150 km/s

13. Evolution of Galaxy Structural Parameters D(z), L(z), μ(z) up to z=1 - Baryonic discs hosted in both small and big DM halos show insignificant size evolution up to z=1 (ΔD/D ~ 0.1±0.2) - Over the same redshift range small rotators experienced a strong luminosity evolution ΔM I ~ -1.2±0.3 while the luminosity of large rotators is seen to remain constant over cosmic time - We conclude that the corresponding strong/weak evolution in galaxy surface brightness is entirely due to a strong/weak luminosity evolution since z=1. This study thus rules out the possibility that SB evolution of discs is caused by a significant size evolution.

14. Conclusions Prospects : Apply the method to a new (~100) HR sample taken by the zCOSMOS survey (P.I. Lilly). - Goal : use deep galaxy surveys in order to explore at the same time both background Cosmological models and sources evolution - Strategy : use observationally measured and theoretically justified correlation between size and rotational velocity of galactic discs to select a set of high redshift standard rods - Results : - If ΔM(z)<0 then Open and EdS cosmologies are excluded - Evolution of baryonic discs is independent of halo mass at least up to z=1. Only galaxy emission properties depend on mass (with small systems experiencing the strongest luminosity evolution).

15. ~40 High Resolution VLT/VIMOS (spectra) + HUBBLE/COSMOS (images)

16. Are we selecting ….