Gauge-invariant gravitational wave modes in pre-big bang cosmology
arXiv:1009.0660 · doi:10.1140/epjc/s10052-010-1445-9
Abstract
The t<0 branch of pre-big bang cosmological scenarios is subject to a gravitational wave instability. The unstable behaviour of tensor perturbations is derived in a very simple way in Hwang's covariant and gauge-invariant formalism developed for extended theories of gravity. A simple interpretation of this instability as the effect of an "antifriction" is given, and it is argued that a universe must eventually enter the expanding phase.
arXiv comment4 pages, latex, to appear in Eur. Phys. J. C
References in corpus (14)
- f(R) Theories Of Gravity
- The Pre-Big Bang Scenario in String Cosmology
- Duality and Dilaton
- The stability of modified gravity models
- de Sitter space and the equivalence between f(R) and scalar-tensor gravity
- On the Stability of a class of Modified Gravitational Models
- Inflationary spectra in generalized gravity: Unified forms
- Evolution of Structures in Generalized Gravity Theories
- Unified Analysis of Cosmological Perturbations in Generalized Gravity
- de Sitter attractors in generalized gravity
- One-loop f(R) Gravitational Modified Models
- Extended quintessence, inflation, and stable de Sitter spaces
- Homogeneous cosmologies in generalized modified gravity
- Gauge-invariant gravitational wave modes in pre-big bang cosmology