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Main Authors: Brizuela, David, de Cesare, Marco, Oficial, Araceli Soler
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2402.15327
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author Brizuela, David
de Cesare, Marco
Oficial, Araceli Soler
author_facet Brizuela, David
de Cesare, Marco
Oficial, Araceli Soler
contents We present a formalism to study linear perturbations of bimetric gravity on any spherically symmetric background, including dynamical spacetimes. The setup is based on the Gerlach-Sengupta formalism for general relativity. Each of the two background metrics is written as a warped product between a two-dimensional Lorentzian metric and the round metric of the two-sphere. The different perturbations are then decomposed in terms of tensor spherical harmonics, which makes the two polarity (axial and polar) sectors decouple. In addition, a covariant notation on the Lorentzian manifold is used so that all expressions are valid for any coordinates. In this theory, there are seven physical propagating degrees of freedom, which, as compared to the two degrees of freedom of general relativity, makes the dynamics much more intricate. In particular, we discuss the amount of gauge and physical degrees of freedom for different polarities and multipoles. Finally, as an interesting application, we analyze static nonbidiagonal backgrounds and derive the corresponding perturbative equations.
format Preprint
id arxiv_https___arxiv_org_abs_2402_15327
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Perturbations of bimetric gravity on most general spherically symmetric spacetimes
Brizuela, David
de Cesare, Marco
Oficial, Araceli Soler
General Relativity and Quantum Cosmology
We present a formalism to study linear perturbations of bimetric gravity on any spherically symmetric background, including dynamical spacetimes. The setup is based on the Gerlach-Sengupta formalism for general relativity. Each of the two background metrics is written as a warped product between a two-dimensional Lorentzian metric and the round metric of the two-sphere. The different perturbations are then decomposed in terms of tensor spherical harmonics, which makes the two polarity (axial and polar) sectors decouple. In addition, a covariant notation on the Lorentzian manifold is used so that all expressions are valid for any coordinates. In this theory, there are seven physical propagating degrees of freedom, which, as compared to the two degrees of freedom of general relativity, makes the dynamics much more intricate. In particular, we discuss the amount of gauge and physical degrees of freedom for different polarities and multipoles. Finally, as an interesting application, we analyze static nonbidiagonal backgrounds and derive the corresponding perturbative equations.
title Perturbations of bimetric gravity on most general spherically symmetric spacetimes
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2402.15327