Speaker:Shun Saito (UC Berkeley)
Time :10:00-11:30
Room :理学部4号館ピロティ前セミナー室

Title:
The BOSS DR9 neutrino mass constraint and Non-local halo bias in the redshift-space power spectrum

Abstract:
Galaxy clustering provides us with an exciting opportunity to access new physics beyond the standard model of particle physics through measurement of cosmic expansion history with the Baryon Acoustic Oscillation (BAO) scale, neutrino mass with shape of the galaxy power spectrum, gravity test with the Redshift-Space Distortion (RSD).
In the first half of the talk, we will present the neutrino mass constraint with data-release 9 (DR9) of the Baryon Oscillation Spectroscopic Survey (BOSS). The BOSS survey is a part of the 3rd generation of the Sloan Digital Sky Survey (SDSS-III) and will give us the largest three-dimensional galaxy map at z~0.7 when the survey finishes in 2014. The BOSS DR9, which is 1st major data release of the BOSS, includes ~260,000 luminous and massive galaxies covering ~3,200 square degrees. In this talk, we will present cosmological constraint with the shape of angle-averaged power spectrum in the BOSS DR9, focusing on the neutrino mass. We carefully investigate model uncertainties including nonlinear gravitational evolution, galaxy bias, and RSD, choice of cosmology, and systematic errors. Our result, m_nutot < 0.34eV (0.82eV) for LCDM (general) cosmology is robust and tight constraint with WMAP7+BOSS plus other distance measurements.
The second part of the talk will focus on an issue in modeling the galaxy power spectrum in redshift space. In order to fully extract cosmological information using the galaxy clustering, it is essential to analyze fully anisotropic power spectrum rather than the spherically-averaged one used in the first half of the talk. Recent studies show that non-local halo bias originating from the tidal field is important to explain the relation between dark matter and halo fields, especially for highly-biased traces expected in the BOSS galaxies. In this talk, we will discuss how to treat such non-local terms in modeling the redshift-space power spectrum of halos in N-body simulation on the basis of perturbation theory. We will present a preliminary result showing a caveat of the importance of such tidal effects.


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Last-modified: 2013-11-20 (水) 11:11:56 (1401d)