THE LYMAN-  FOREST AS A PROBE OF FUNDAMENTAL PHYSICS MATTEO VIEL Shanghai, 16 March Cosmological significance of the Lyman-  forest 2. LUQAS: The observational sample 3.Hydro-dynamical simulations of the Lyman-  forest 4.Cosmological parameters – Implications for: inflation, neutrinos, gravitinos, warm dark matter particles With M. Haehnelt, J. Lesgourgues, S. Matarrese, A. Riotto, V. Springel, J. Weller

GOAL: the primordial dark matter power spectrum Tegmark & Zaldarriaga 2002 CMB physics z = 1100 dynamics Ly  physics z < 6 dynamics + termodynamics CMB + Lyman  Long lever arm Constrain spectral index and shape Relation: P FLUX (k) - P MATTER (k) ?? Continuum fitting Temperature, metals, noise

before WMAP Croft et al WMAP Verde et al the WMAP era Tilt in the spectrum n<1 ? Running spectral index dn/dlnk < 0 ?

DM STARS GAS NEUTRAL HYDROGEN  m = 0.26   = 0.74  b = H = 72 km/sec/Mpc - 60 Mpc/h COSMOS computer – DAMTP (Cambridge)

The LUQAS sample -I Kim, MV, Haehnelt, Carswell, Cristiani, 2004, MNRAS, 347, 355 Large sample Uves Qso Absorption Spectra (LP-UVES program P.I. J. Bergeron) high resolution 0.05 Angstrom, high S/N > 50 low redshift, =2.25,  z = Nr. spectra redshift

The LUQAS sample –II systematic errors Effective optical depth = exp (-  eff ) Power spectrum of F/ Low resolution SDSS like spectra High resolution UVES like spectra

Hydro-simulations: scalings T = T 0 ( 1 +  )  Effective optical depth P FLUX (k) = b 2 (k) P MATTER (k) Viel, Haehnelt, Springel, MNRAS, 2004, 354, 684

Hydro-simulations: what have we learnt? Many uncertainties which contribute more or less equally (statistical error is not an issue!) Statistical error4% Systematic errors~ 15 %  eff (z=2.125)=0.17 ± %  eff (z=2.72) = ± %  = 1.3 ± % T 0 = ± K 3 % Method5 % Numerical simulations8 % Further uncertainties5 % ERRORS CONTRIBUTION TO FLUCT. AMPL.

Cosmological implications: combining the forest data with CMB - I n = 1.01 ± 0.02 ± 0.06  8 = 0.93 ± 0.03 ± 0.09 Statistical error Systematic error SDSS Seljak et al MV, Haehnelt, Springel 2004 Note that the flux bispectrum analysis agrees with these values MV, Matarrese, Heavens, Haehnelt, Kim, Springel, Hernquist, 2004

Cosmological implications: combining the forest data with CMB - II SDSS Seljak et al  8 = 0.93 ± 0.07 n=0.99 ± 0.03  8 = 0.90 ± 0.03 n=0.98 ± 0.02 n run = ± n run =-0.033± d n s / d ln k MV, Weller, Haehnelt, MNRAS, 2004, 355, L23

Cosmological implications: constraints on slow-roll inflation - III SDSS Seljak et al r < 0.45 (95% lim.) r = 0.50 ± 0.30 No evidence for gravity waves T/S = T/S V = inflaton potential MV, Weller, Haehnelt, MNRAS, 2004, 355, L23

Cosmological implications: Warm Dark Matter particles-I  CDM WDM 0.5 keV 30 comoving Mpc/h z=3 MV, Lesgourgues, Haehnelt, Matarrese, Riotto, PRD in press k FS ~ 5 T v /T x (m x /1keV) Mpc -1 k FS ~ 1.5 (m x /100eV) h/Mpc In general if light gravitinos Set by relativistic degrees of freedom at decoupling

Cosmological implications: Warm Dark Matter particles-II  WDM  CWDM (gravitino like) Set limits on the scale of Supersymmetry breaking   susy < 260 TeV m WDM > 550 eV > 2keV sterile neutrino < 16 eV gravitino Scale of free streaming  gravitino /  DM

Cosmological implications: constraints on neutrinos  m (eV) = 0.33 ± 0.27 WMAP + 2dF + Lyman- 

HPM simulations of the forest Full hydro 200^3 part. HPM PMGRID=600 HPM PMGRID=400 FLUX POWER

HIGH RESOLUTION HIGH S/N vs LOW RESOLUTION LOW S/N

LUQAS vs SDSS

SUMMARY 1.LUQAS: a unique high resolution view on the Universe at z= Hydro-dynamical simulations of the Lyman-  forest. Systematic Errors? Differences between hydro codes? 3.Cosmological parameters: no fancy things going on  8 = 0.93 n = 1 no running substantial agreement between SDSS and LUQAS but SDSS has smaller error bars not because of the larger sample but because of the different theoretical modelling Constraints on inflationary models, neutrinos and WDM

HPM simulations of the forest-I Gnedin & Hui 1998 equation of motion for gas element if T = T 0 ( 1 +  ) 

Density Temperature No FeedbackFeedback Feedback effects: Galactic winds

Feedback effects: Galactic winds-III Line widths distribution Column density distribution function

Metal enrichment CIV systems at z=3 Strong Feedback  = Role of the UV background Soft background ---- Role of different feedback  =1  =0  =0.1 Mori, Ferrara, Madau 2000; Rauch, Haehnelt, Steinmetz 1996; Schaye et al. 2003

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