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Title: Observational signatures of gravitational couplings in DBI inflation

Abstract

In scalar-tensor theories the scalar fields generically couple nontrivially to gravity. We study the observable properties of inflationary models with nonminimally coupled inflaton and Dirac-Born-Infeld (DBI) kinetic term. Within the assumptions of the priors of our Monte-Carlo simulations we find these models can generate new interesting observable signatures. Our discussion focuses on string theory inspired phenomenological models of relativistic D-brane inflation. While successful string theory constructions of ultraviolet DBI brane inflation remain elusive, we show that in suitable regions of the parameter space it is possible to use cosmological observables to probe the nonminimal coupling. Fortunately, the most observationally promising range of parameters include models yielding intermediate levels of non-Gaussianity in the range consistent with WMAP 5-year data, and to be constrained further by the Planck satellite.

Authors:
 [1]; ;  [1]
  1. Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568 (Japan)
Publication Date:
OSTI Identifier:
21409045
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 81; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevD.81.023512; (c) 2010 The American Physical Society; Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BORN-INFELD THEORY; COMPUTERIZED SIMULATION; COUPLING; D-BRANES; GRAVITATION; INFLATIONARY UNIVERSE; MONTE CARLO METHOD; RELATIVISTIC RANGE; SCALAR FIELDS; STRING MODELS; STRING THEORY; ULTRAVIOLET RADIATION; BRANES; CALCULATION METHODS; COMPOSITE MODELS; COSMOLOGICAL MODELS; ELECTROMAGNETIC RADIATION; ENERGY RANGE; EXTENDED PARTICLE MODEL; MATHEMATICAL MODELS; M-THEORY; PARTICLE MODELS; QUARK MODEL; RADIATIONS; SIMULATION

Citation Formats

Easson, Damien A, Department of Physics, and School of Earth and Space Exploration, and Beyond Center, Arizona State University, Tempe, Arizona, 85287-1504, Mukohyama, Shinji, and Powell, Brian A. Observational signatures of gravitational couplings in DBI inflation. United States: N. p., 2010. Web. doi:10.1103/PHYSREVD.81.023512.
Easson, Damien A, Department of Physics, and School of Earth and Space Exploration, and Beyond Center, Arizona State University, Tempe, Arizona, 85287-1504, Mukohyama, Shinji, & Powell, Brian A. Observational signatures of gravitational couplings in DBI inflation. United States. https://doi.org/10.1103/PHYSREVD.81.023512
Easson, Damien A, Department of Physics, and School of Earth and Space Exploration, and Beyond Center, Arizona State University, Tempe, Arizona, 85287-1504, Mukohyama, Shinji, and Powell, Brian A. 2010. "Observational signatures of gravitational couplings in DBI inflation". United States. https://doi.org/10.1103/PHYSREVD.81.023512.
@article{osti_21409045,
title = {Observational signatures of gravitational couplings in DBI inflation},
author = {Easson, Damien A and Department of Physics, and School of Earth and Space Exploration, and Beyond Center, Arizona State University, Tempe, Arizona, 85287-1504 and Mukohyama, Shinji and Powell, Brian A},
abstractNote = {In scalar-tensor theories the scalar fields generically couple nontrivially to gravity. We study the observable properties of inflationary models with nonminimally coupled inflaton and Dirac-Born-Infeld (DBI) kinetic term. Within the assumptions of the priors of our Monte-Carlo simulations we find these models can generate new interesting observable signatures. Our discussion focuses on string theory inspired phenomenological models of relativistic D-brane inflation. While successful string theory constructions of ultraviolet DBI brane inflation remain elusive, we show that in suitable regions of the parameter space it is possible to use cosmological observables to probe the nonminimal coupling. Fortunately, the most observationally promising range of parameters include models yielding intermediate levels of non-Gaussianity in the range consistent with WMAP 5-year data, and to be constrained further by the Planck satellite.},
doi = {10.1103/PHYSREVD.81.023512},
url = {https://www.osti.gov/biblio/21409045}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 2,
volume = 81,
place = {United States},
year = {2010},
month = {1}
}