Scalar mode propagation in modified gravity with a scalar field
Cosmology and Nongalactic Astrophysics
2009-11-05 v1 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
High Energy Physics - Theory
Abstract
We study the propagation of the scalar modes around a Friedmann-Lemaitre-Robertson-Walker universe for general modifications of gravity in the presence of a real scalar field. In general, there will be two propagating scalar perturbation fields, which will have in total four degrees of freedom. Two of these degrees will have a superluminal propagation--with k-dependent speed of propagation--whereas the other two will travel with the speed of light. Therefore, the scalar degrees of freedom do not modify the general feature of modified gravity models: the appearance of modes whose frequency depends on the second power of the modulus of the wave vector. Constraints are given and special cases are discussed.
Cite
@article{arxiv.0907.5378,
title = {Scalar mode propagation in modified gravity with a scalar field},
author = {Antonio De Felice and Teruaki Suyama},
journal= {arXiv preprint arXiv:0907.5378},
year = {2009}
}
Comments
13 pages, 1 figure, uses RevTeX