Cosmological parameters from SDSS and WMAP
Abstract
We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.
Cite
@article{arxiv.astro-ph/0310723,
title = {Cosmological parameters from SDSS and WMAP},
author = {M. Tegmark and M. Strauss and M. Blanton and K. Abazajian and S. Dodelson and H. Sandvik and X. Wang and D. Weinberg and I. Zehavi and N. Bahcall and F. Hoyle and D. Schlegel and R. Scoccimarro and M. Vogeley and A. Berlind and T. Budavari and A. Connolly and D. Eisenstein and D. Finkbeiner and J. Frieman and J. Gunn and L. Hui and B. Jain and D. Johnston and S. Kent and H. Lin and R. Nakajima and R. Nichol and J. Ostriker and A. Pope and R. Scranton and U. Seljak and R. Sheth and A. Stebbins and A. Szalay and I. Szapudi and Y. Xu},
journal= {arXiv preprint arXiv:astro-ph/0310723},
year = {2016}
}
Comments
Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.html