Inflationary non-Gaussianities in the most general second-order scalar-tensor theories

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.083504· OSTI ID:21607863

De Felice, Antonio; Tsujikawa, Shinji ^[1]

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1. Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

For very general scalar-field theories in which the equations of motion are at second order, we evaluate the three-point correlation function of primordial scalar perturbations generated during inflation. We show that the shape of non-Gaussianities is well approximated by the equilateral type. The equilateral nonlinear parameter f{sub NL}{sup equil} is derived on the quasi-de Sitter background, where the slow-variation parameters are much smaller than unity. We apply our formula for f{sub NL}{sup equil} to a number of single-field models of inflation--such as k-inflation, k-inflation with Galileon terms, potential-driven Galileon inflation, nonminimal coupling models (including field-derivative coupling models), and Gauss-Bonnet gravity.

• OSTI ID: 21607863
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CORRELATION FUNCTIONS
COUPLING
DE SITTER SPACE
DIFFERENTIAL EQUATIONS
DISTURBANCES
EQUATIONS
EQUATIONS OF MOTION
FIELD THEORIES
FUNCTIONS
GRAVITATION
MATHEMATICAL SPACE
NONLINEAR PROBLEMS
PARTIAL DIFFERENTIAL EQUATIONS
PERTURBATION THEORY
SCALAR FIELDS
SPACE