Inflationary perturbations in Palatini generalized gravity
File(s)
Accepted version
Author(s)
Tamanini, Nicola
Contaldi, Carlo R
Type
Journal Article
Abstract
We examine the generation of primordial perturbations during an inflationary epoch in generalized theories of gravity when the equations of motion are derived using the Palatini variational principle. Both
f
(
R
)
and scalar-tensor theories are considered, and we compare our results with those obtained under the conventional metric formalism. Nonlinear generalizations of the action lead to different theories under the two variational choices, and we obtain distinct results for scalar and tensor spectral indices and their ratio. We find the following general result: Inflation driven solely by
f
(
R
)
modifications does not result in suitable curvature perturbations, while scalar-tensor theories generate nearly scalar invariant curvature perturbations but no tensor modes.
f
(
R
)
and scalar-tensor theories are considered, and we compare our results with those obtained under the conventional metric formalism. Nonlinear generalizations of the action lead to different theories under the two variational choices, and we obtain distinct results for scalar and tensor spectral indices and their ratio. We find the following general result: Inflation driven solely by
f
(
R
)
modifications does not result in suitable curvature perturbations, while scalar-tensor theories generate nearly scalar invariant curvature perturbations but no tensor modes.
Date Issued
2011-02-08
Date Acceptance
2011-02-01
Citation
Physical Review D: Particles, Fields, Gravitation and Cosmology, 2011, 83 (4)
ISSN
1550-2368
Publisher
American Physical Society
Journal / Book Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
Volume
83
Issue
4
Copyright Statement
© 2011 American Physical Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000287078400005&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Physics, Particles & Fields
Physics
COSMOLOGICAL PERTURBATIONS
SCALAR-TENSOR
F(R) THEORIES
MODEL
F(R)-GRAVITY
FORMULATION
EINSTEIN
SPECTRA
ENERGY
Publication Status
Published
Article Number
ARTN 044018