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Center for Theoretical Physics University of Provence Marseille

Testing Cosmological Models with High Redshift Galaxies. Christian Marinoni. Center for Theoretical Physics University of Provence Marseille. ?. ?. New source. ?. Inhomogeneus universe. New gravitational physics. Nature of Dark Energy. Metric RW line element. Gravity

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Center for Theoretical Physics University of Provence Marseille

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  1. Testing Cosmological Models with High Redshift Galaxies Christian Marinoni Center for Theoretical Physics University of Provence Marseille

  2. ? ? New source ? Inhomogeneus universe New gravitational physics Nature of Dark Energy Metric RW line element Gravity Field equations

  3. Outline • 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

  4. δ Field Marinoni et al. 2008 A&A in press (arXiv 0802.1838) 2DFGRS/SDSS stop here Gaussian Filter R=2Mpc)

  5. Testing gravity with second order statistics : VVDS LeFevre et al. 05 <Z>=0.75 ~6,000 galaxies f=0.9±0.4 σ=400±50 km/s (Guzzo et al. 2008 Nature 2008) 2dFGRS (Colless et al. 00) <Z>=0.1 120,000 galaxies f=0.5±0.1 σ=390±50 km/s (Peacock et al. 2001, Nature)

  6. Predicted constraints from SPACE missison Constraining the physics behind acceleration In linear theory In principle, f can reveal the physical origin of the acceleration

  7. Mass skewness Juszkievicz et al. 1993 Hivon et al. 1995 Biasing at high z cannot be described in terms of a single constant Galaxy skewness Marinoni et al. 2005, A&A, 442, 801 Testing gravity with third order statistics : Skewness R=10h-1Mpc Galaxy fluctuations were significantly non Gaussian even at early times Marinoni et al. 2008 A&A in press (arXiv:0802.1838) Verde et al. 01 Croton et al. 2005 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

  8. Standard Rod Selection Theory predicts : Observationally Confirmed Saintonge et al. 2008 A&A,478, 57 Metric constraints using the kinematics of high redshift disc galaxies Marinoni, Saintonge, Giovanelli et al. 2007 A&A , 478, 41 Saintonge, Master, Marinoni et al. 2007 A&A, 478, 57 Marinoni, Saintonge Contini et al. 2007 A&A , 478, 71 Angular Diameter Test D

  9. The 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%

  10. These two quantities are not independent, as they are related by the cosmic consistency relation (e.g. Stebbins 2007) where Violation of consistency might indicate Non-RW geometry Spatial curvature Tests of the Cosmological Principle Many cosmological tests make use of only two functions of redshift The angular diameter distance dA(z) and the radial comoving distance r(z)

  11. The consistency tests with high velocity rotators Sinfoni + HST ~30 disc galaxies hosting a supernovae in the zCOSMOS field VIMOS+ Cosmos

  12. 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 Implementation Strategy: HST/Cosmos imaging survey: Z=0.5 VLT HST Z=0.9 HR Spectroscopy (VIMOS)

  13. Comparison with the predicted angular evolution in the standard ΛCDM background 0<v(km/s)<100 100<v(km/s)<200 Best fitting model ΛCDM Preliminary data Standard Rod Selection

  14. Cosmological Constraints from Preliminary data • Observational constraints: • luminosity emitted per unit mass • was higher In the past. • SB evolution as inferred from data • Which is the region of the • cosmological parameter space • which is compatible with these • external constraints? 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 !!!

  15. Conclusions • 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) - 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! • 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

  16. EVOLUTION According to theory (analytic models and simulations) big baryonic discs already completed their evolution before z=1 Chiappini, Matteucci & Gratton 1997 Boissier & Prantzos 2001 Bowens & Silk 2001 Ferguson & Clarke 2003 Somerville 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 `matter density Test’ Excluded Region

  17. Structural Parameters Evolution 0<V(km/s)<100 100<V(km/s)<200

  18. Theoretical Interpretation:Which is the physical mechanism governing biasing evolution? Merging (Mo & White 96 Matarrese et al. 97) Istantaneous Star Formation (Blanton et al 02) Gravity (Dekel and Rees 88 Tegmark & Peebles 98)

  19. Field Reconstruction Technique

  20. Extraction of Biasing Z=1.1-1.5 Z=0.7-1.1

  21. Statistical Strategy : Analyze fluctuations moments 1) TESTING GRAVITY (GR) Linear Growth of CDM structures Fundamental variable describing the LSS structure Linear Approximation Newtonian Regime Pressureless Matter fluid Adiabatic perturbation It exists an unstable growing solution

  22. Evolution of low order moments Volume-limited sample M<-20+5log h Second Moment 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 Marinoni et al. A&A 2005 Third Moment Galaxy distribution was significantly non Gaussian even at early times Marinoni et al. A&A 2007

  23. The outstanding problem : Dark Energy Dark What do we know ? Smooth on cluster scales Accelerating the Universe { - The Fine Tuning Problem Particle physics theory currently provides no understanding of why the vacuum energy density is so small: - The Cosmic Coincidence Problem Theory 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?

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