Observational signatures of gravitational couplings in DBI inflation

Journal Article · Fri Jan 15 04:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.023512· OSTI ID:21409045

Easson, Damien A ^[1]; Mukohyama, Shinji; Powell, Brian A ^[1]

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1. Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8568 (Japan)

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.

• OSTI ID: 21409045
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 2 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTRONOMY AND ASTROPHYSICS
BORN-INFELD THEORY
BRANES
CALCULATION METHODS
COMPOSITE MODELS
COMPUTERIZED SIMULATION
COSMOLOGICAL MODELS
COUPLING
D-BRANES
ELECTROMAGNETIC RADIATION
ENERGY RANGE
EXTENDED PARTICLE MODEL
GRAVITATION
INFLATIONARY UNIVERSE
M-THEORY
MATHEMATICAL MODELS
MONTE CARLO METHOD
PARTICLE MODELS
QUARK MODEL
RADIATIONS
RELATIVISTIC RANGE
SCALAR FIELDS
SIMULATION
STRING MODELS
STRING THEORY
ULTRAVIOLET RADIATION