2004/07/19 by Uroš Seljak, U. Seljak, A. Makarov +38 · 51 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.71.103515
published as Phys.Rev.D71:103515,2005 · 21 pages, 17 figures, submitted to PRD
arxiv created 2004/07/19 · openalex publication_date 2005/05/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
We combine the constraints from the recent Ly\ensuremathα forest analysis of the Sloan Digital Sky Survey (SDSS) and the SDSS galaxy bias analysis with previous constraints from SDSS galaxy clustering, the latest supernovae, and 1st year WMAP cosmic microwave background anisotropies. We find significant improvements on all of the cosmological parameters compared to previous constraints, which highlights the importance of combining Ly\ensuremathα forest constraints with other probes. Combining WMAP and the Ly\ensuremathα forest we find for the primordial slope ns=0.98\ifmmode±\else\textpm\fi0.02. We see no evidence of running, dn/dlnk=\ensuremath-0.003\ifmmode±\else\textpm\fi0.010, a factor of 3 improvement over previous constraints. We also find no evidence of tensors, r<0.36 (95% c.l.). Inflationary models predict the absence of running and many among them satisfy these constraints, particularly negative curvature models such as those based on spontaneous symmetry breaking. A positive correlation between tensors and primordial slope disfavors chaotic inflation-type models with steep slopes: while the V\ensuremath∝\ensuremathφ2 model is within the 2-sigma contour, V\ensuremath∝\ensuremathφ4 is outside the 3-sigma contour. For the amplitude we find \ensuremathσ8=0.90\ifmmode±\else\textpm\fi0.03 from the Ly\ensuremathα forest and WMAP alone. We find no evidence of neutrino mass: for the case of 3 massive neutrino families with an inflationary prior, \ensuremath∑m_\ensuremathν<0.42 eV and the mass of lightest neutrino is m1<0.13 eV at 95% c.l. For the 3 massless +1 massive neutrino case we find m_\ensuremathν<0.79 eV for the massive neutrino, excluding at 95% c.l. all neutrino mass solutions compatible with the LSND results. We explore dark energy constraints in models with a fairly general time dependence of dark energy equation of state, finding \ensuremathΩ_\ensuremathλ=0.72\ifmmode±\else\textpm\fi0.02, w(z=0.3)=\ensuremath-0.98_\ensuremath-0.12+0.10, the latter changing to w(z=0.3)=\ensuremath-0.92_\ensuremath-0.10+0.09 if tensors are allowed. We find no evidence for variation of the equation of state with redshift, w(z=1)=\ensuremath-1.03_\ensuremath-0.28+0.21. These results rely on the current understanding of the Ly\ensuremathα forest and other probes, which need to be explored further both observationally and theoretically, but extensive tests reveal no evidence of inconsistency among different data sets used here.