Cosmological perturbations in massive bigravity
We present a comprehensive analysis of classical scalar, vector and tensor cosmological perturbations in ghost-free massive bigravity. In particular, we find the full evolution equations and analytical solutions in a wide range of regimes. We show that there are viable cosmological backgrounds but,...
| Main Authors: | , |
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| Format: | Journal article |
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2014
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| _version_ | 1826267705019203584 |
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| author | Lagos, M Ferreira, P |
| author_facet | Lagos, M Ferreira, P |
| author_sort | Lagos, M |
| collection | OXFORD |
| description | We present a comprehensive analysis of classical scalar, vector and tensor cosmological perturbations in ghost-free massive bigravity. In particular, we find the full evolution equations and analytical solutions in a wide range of regimes. We show that there are viable cosmological backgrounds but, as has been found in the literature, these models generally have exponential instabilities in linear perturbation theory. However, it is possible to find stable scalar cosmological perturbations for a very particular choice of parameters. For this stable subclass of models we find that vector and tensor perturbations have growing solutions. We argue that special initial conditions are needed for tensor modes in order to have a viable model. |
| first_indexed | 2024-03-06T20:58:16Z |
| format | Journal article |
| id | oxford-uuid:3a01fd1a-dbd5-4c5f-bd59-21a17e323718 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T20:58:16Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | oxford-uuid:3a01fd1a-dbd5-4c5f-bd59-21a17e3237182022-03-26T13:58:56ZCosmological perturbations in massive bigravityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3a01fd1a-dbd5-4c5f-bd59-21a17e323718Symplectic Elements at Oxford2014Lagos, MFerreira, PWe present a comprehensive analysis of classical scalar, vector and tensor cosmological perturbations in ghost-free massive bigravity. In particular, we find the full evolution equations and analytical solutions in a wide range of regimes. We show that there are viable cosmological backgrounds but, as has been found in the literature, these models generally have exponential instabilities in linear perturbation theory. However, it is possible to find stable scalar cosmological perturbations for a very particular choice of parameters. For this stable subclass of models we find that vector and tensor perturbations have growing solutions. We argue that special initial conditions are needed for tensor modes in order to have a viable model. |
| spellingShingle | Lagos, M Ferreira, P Cosmological perturbations in massive bigravity |
| title | Cosmological perturbations in massive bigravity |
| title_full | Cosmological perturbations in massive bigravity |
| title_fullStr | Cosmological perturbations in massive bigravity |
| title_full_unstemmed | Cosmological perturbations in massive bigravity |
| title_short | Cosmological perturbations in massive bigravity |
| title_sort | cosmological perturbations in massive bigravity |
| work_keys_str_mv | AT lagosm cosmologicalperturbationsinmassivebigravity AT ferreirap cosmologicalperturbationsinmassivebigravity |