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Title: Is there scale-dependent bias in single-field inflation?

Abstract

Scale-dependent halo bias due to local primordial non-Gaussianity provides a strong test of single-field inflation. While it is universally understood that single-field inflation predicts negligible scale-dependent bias compared to current observational uncertainties, there is still disagreement on the exact level of scale-dependent bias at a level that could strongly impact inferences made from future surveys. In this paper, we clarify this confusion and derive in various ways that there is exactly zero scale-dependent bias in single-field inflation. Much of the current confusion follows from the fact that single-field inflation does predict a mode coupling of matter perturbations at the level of f{sub NL}{sup local}; ≈ −5/3, which naively would lead to scale-dependent bias. However, we show explicitly that this mode coupling cancels out when perturbations are evaluated at a fixed physical scale rather than fixed coordinate scale. Furthermore, we show how the absence of scale-dependent bias can be derived easily in any gauge. This result can then be incorporated into a complete description of the observed galaxy clustering, including the previously studied general relativistic terms, which are important at the same level as scale-dependent bias of order f{sub NL}{sup local} ∼ 1. This description will allow us to draw unbiased conclusions about inflation frommore » future galaxy clustering data.« less

Authors:
;  [1];  [2]
  1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
  2. Canadian Institute for Theoretical Astrophysics, Toronto, ON M5S 3H8 (Canada)
Publication Date:
OSTI Identifier:
22525253
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2015; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COORDINATES; COSMOLOGICAL INFLATION; COUPLING; CURRENTS; DISTURBANCES; GALAXY CLUSTERS; GENERAL RELATIVITY THEORY; INFLATIONARY UNIVERSE; RELATIVISTIC RANGE

Citation Formats

De Putter, Roland, Doré, Olivier, and Green, Daniel, E-mail: rdputter@caltech.edu, E-mail: Olivier.P.Dore@jpl.nasa.gov, E-mail: drgreen@cita.utoronto.ca. Is there scale-dependent bias in single-field inflation?. United States: N. p., 2015. Web. doi:10.1088/1475-7516/2015/10/024.
De Putter, Roland, Doré, Olivier, & Green, Daniel, E-mail: rdputter@caltech.edu, E-mail: Olivier.P.Dore@jpl.nasa.gov, E-mail: drgreen@cita.utoronto.ca. Is there scale-dependent bias in single-field inflation?. United States. doi:10.1088/1475-7516/2015/10/024.
De Putter, Roland, Doré, Olivier, and Green, Daniel, E-mail: rdputter@caltech.edu, E-mail: Olivier.P.Dore@jpl.nasa.gov, E-mail: drgreen@cita.utoronto.ca. Thu . "Is there scale-dependent bias in single-field inflation?". United States. doi:10.1088/1475-7516/2015/10/024.
@article{osti_22525253,
title = {Is there scale-dependent bias in single-field inflation?},
author = {De Putter, Roland and Doré, Olivier and Green, Daniel, E-mail: rdputter@caltech.edu, E-mail: Olivier.P.Dore@jpl.nasa.gov, E-mail: drgreen@cita.utoronto.ca},
abstractNote = {Scale-dependent halo bias due to local primordial non-Gaussianity provides a strong test of single-field inflation. While it is universally understood that single-field inflation predicts negligible scale-dependent bias compared to current observational uncertainties, there is still disagreement on the exact level of scale-dependent bias at a level that could strongly impact inferences made from future surveys. In this paper, we clarify this confusion and derive in various ways that there is exactly zero scale-dependent bias in single-field inflation. Much of the current confusion follows from the fact that single-field inflation does predict a mode coupling of matter perturbations at the level of f{sub NL}{sup local}; ≈ −5/3, which naively would lead to scale-dependent bias. However, we show explicitly that this mode coupling cancels out when perturbations are evaluated at a fixed physical scale rather than fixed coordinate scale. Furthermore, we show how the absence of scale-dependent bias can be derived easily in any gauge. This result can then be incorporated into a complete description of the observed galaxy clustering, including the previously studied general relativistic terms, which are important at the same level as scale-dependent bias of order f{sub NL}{sup local} ∼ 1. This description will allow us to draw unbiased conclusions about inflation from future galaxy clustering data.},
doi = {10.1088/1475-7516/2015/10/024},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 10,
volume = 2015,
place = {United States},
year = {2015},
month = {10}
}