Nonlinear evolutions and non-Gaussianity in generalized gravity

Journal Article · Wed Jun 15 04:00:00 EDT 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.71.123511· OSTI ID:20709526

Koh, Seoktae ^[1]; Kim, Sang Pyo ^[1]; Song, Doo Jong ^[2]

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1. Department of Physics, Kunsan National University, Kunsan 573-701 (Korea, Republic of)
2. Korea Astronomy Observatory, Daejeon 305-348 (Korea, Republic of)

We use the Hamilton-Jacobi theory to study the nonlinear evolutions of inhomogeneous spacetimes during inflation in generalized gravity. We find the exact solutions to the lowest order Hamilton-Jacobi equation for special scalar potentials and introduce an approximation method for general potentials. The conserved quantity invariant under a change of timelike hypersurfaces proves useful in dealing with gravitational perturbations. In the long-wavelength approximation, we find a conserved quantity related to the new canonical variable that makes the Hamiltonian density vanish, and calculate the non-Gaussianity in generalized gravity. The slow-roll inflation models with a single scalar field in generalized gravity predict too small non-Gaussianity to be detected by future CMB experiments.

• OSTI ID: 20709526
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DISTURBANCES
EVOLUTION
EXACT SOLUTIONS
GRAVITATION
HAMILTON-JACOBI EQUATIONS
HAMILTONIANS
INFLATIONARY UNIVERSE
NONLINEAR PROBLEMS
POTENTIALS
SCALAR FIELDS
SCALARS
SPACE-TIME
WAVELENGTHS