Cosmological constraints on neutrino mass Francesco De Bernardis University of Rome “Sapienza” Incontro Nazionale Iniziative di Fisica Astroparticellare Frascati – 22/23 Giugno 2010

Matter: Cosmic balance

Neutrino masses from cosmology - Cosmology is sensitive to absolute neutrino mass. - Constraints from Cosmology are stronger than those from particle physics even if indirect and model dependent: CMB+LRG+Sne+HST CMB+LSS+BAOs+SNe+Ly-  E.Komatsu et al G.L.Fogli et al.,Phys.Rev.D75:053001, 2007

Neutrino mass effect on Cosmology is connected mainly to the free-streaming that cause neutrino to erase their density perturbations on scales smaller than the free-streaming length. Because of free streaming massive neutrinos are a matter component that doesn’t contribute to clustering on small scales… Lesgourgues, Pastor 2006 Massive neutrinos and Cosmological Observables Free streaming

Massive neutrinos and Cosmological Observables- Matter power spectrum As a consequence of free-streamingneutrino mass leave a distinctive imprint on clustering of structure. Effects of free streaming are clearly visible in the statistical properties of matter distribution.

Halo Model The clustering of galaxies is biased with respect to that of dark matter. - Galaxies form inside dark matter halos. A galaxy of luminosity L can form in halos of mass M with probability given by. - The halo distribution itself is biased with respect to dark matter: Halo bias:. - The bias of galaxies depends on their luminosity, with more luminous galaxies being more clustered*: * 2dF: Morger et al, MNRAS 328,64, 2001 SDSS:Zehavi et al,ApJ 571, 172 (2002)

Halo Model The halo bias can be calculated for a given cosmological model: - The probability distribution can be extimated by galaxy-galaxy lensing or galaxy luminosity function. - We don’t know the luminosity L * of the unbiased galaxies (b=1): Sheth, Mo, Tormen, MNRAS, 323 (2001)

Sloan Digital Sky Survey DEEP2 Subaru Deep Field Dataset and analysis Cooray, MNRAS 365: (2006) Cooray, Ouchi, MNRAS 369: (2006) Davis, M. et al. 2003, SPIE, 4834, 161 Miyazaki, S. et al. 2002, PASJ, 54, 833 Seljak et al., Phys.Rev.D71:043511,2005

b * =b * (z): we don’t know b * ; we treat it as a free parameter for each redshift. Dataset and analysis - Analysis of WMAP5 CMB data, P(k) shape from SDSS + b(L) data. De Bernardis F., Serra P., Cooray A., Melchiorri A.- Phys.Rev.D78:083535,2008 – arXiv: Z=0.05 Z=1.0 Z=3.8

b * =b * (z): we don’t know L * ; we treat it as a free parameter for each redshift. Dataset and analysis - Analysis of WMAP5 CMB data, P(k) shape from SDSS + b(L) data. De Bernardis F., Serra P., Cooray A., Melchiorri A.- Phys.Rev.D78:083535,2008 – arXiv: Note that WMPA5+SDSS+2dF+SNe gives: (Komatsu et al. Astrophys.J.Suppl.180: ,2009)

Dataset and analysis Structure formation depends also on dark energy equation of state: there is a degeneracy with neutrino mass. De Bernardis F., Serra P., Cooray A., Melchiorri A.- Phys.Rev.D78:083535,2008 – arXiv:

Dataset and analysis The degeneracy can be partially broken adding more datasets: - HST: Hubble Space Telescope prior on H 0 - Sne: luminosity distance measurements from Supernovae Ia - ACBAR: CMB data from Arcminute Cosmology Bolometer Receiver WMAP+SDSS+b(z) +ACBAR+HST+Sne De Bernardis F., Serra P., Cooray A., Melchiorri A.- Phys.Rev.D78:083535,2008 – arXiv:

Conclusion: Comparison to other cosmological results

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