Slosar, Anže and Hirata, Christopher and Seljak, Uroš and Ho, Shirley and Padmanabhan, Nikhil (2008) Constraints on local primordial non-Gaussianity from large scale structure. Journal of Cosmology and Astroparticle Physics, 2008 (8). Art. No. 031. ISSN 1475-7516 http://resolver.caltech.edu/CaltechAUTHORS:SLOjcap08
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Recent work has shown that the local non-Gaussianity parameter fNL induces a scale dependent bias, whose amplitude is growing with scale. Here we first rederive this result within the context of the peak–background split formalism and show that it only depends on the assumption of universality of the mass function, assuming that the halo bias only depends on the mass. We then use the extended Press–Schechter formalism to argue that this assumption may be violated and that the scale dependent bias will depend on other properties, such as the merging history of halos. In particular, in the limit of recent mergers we find that the effect is suppressed. Next we use these predictions in conjunction with a compendium of large scale data to put a limit on the value of fNL. When combining all data assuming that the halo occupation depends only on the halo mass, we get a limit of -29 (-65)<fNL<+70 (+93) at 95% (99.7%) confidence. While we use a wide range of data sets, our combined result is dominated by the signal from the SDSS photometric quasar sample. If the latter are modeled as recent mergers then the limits weaken to -31 (-96)<fNL<+70 (+96). These limits are comparable to the strongest current limits from the Wilkinson Anisotropy Probe (WMAP) five-year analysis, with no evidence of a positive signal in fNL. While the method needs to be thoroughly tested against large scale structure simulations with realistic quasar and galaxy formation models, our results indicate that this is a competitive method relative to the cosmic microwave background one and should be further pursued both observationally and theoretically.
|Additional Information:||Copyright © Institute of Physics and IOP Publishing Limited 2008. Received 4 June 2008, accepted for publication 29 July 2008. Published 27 August 2008. We acknowledge useful discussions with Niayesh Afshordi and Dan Babich. AS is supported by the inaugural BCCP Fellowship. CH is supported by the US Department of Energy under contract DE-FG03-02-ER40701. NP is supported by a Hubble Fellowship HST.HF-01200.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. Part of this work was supported by the Director, Office of Science, of the US Department of Energy under Contract No. DE-AC02-05CH11231. US is supported by the Packard Foundation and NSF CAREER-0132953 and by Swiss National Foundation under contract 200021-116696/1. Funding for the Sloan Digital Sky Survey (SDSS) and SDSS-II has been provided by the Alfred P Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Web site is http://www.sdss.org/. The SDSS is managed by the Astrophysical Research Consortium (ARC) for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, The University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, The Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max Planck Institute for Astronomy (MPIA), the Max Planck Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington. E-print number: 0805.3580|
|Subject Keywords:||inflation; physics of the early universe; power spectrum|
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|Deposited By:||Archive Administrator|
|Deposited On:||31 Aug 2008 06:14|
|Last Modified:||26 Dec 2012 10:15|
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