Failures of homogeneous and isotropic cosmologies in extended quasidilaton massive gravity
We analyze the extended quasidilaton massive gravity model around a Friedmann-Lemaître-Robertson- Walker cosmological background. We present a careful stability analysis of asymptotic fixed points. We find that the traditional fixed point cannot be approached dynamically, except from a perfectly fin...
| Authors: | , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2017 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/44176 |
| Online Access: | http://hdl.handle.net/11336/44176 |
| Access Level: | Open access |
| Keyword: | MODIFIED GRAVITY COSMOLOGY PERTURBATION THEORY STABILITY https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Summary: | We analyze the extended quasidilaton massive gravity model around a Friedmann-Lemaître-Robertson- Walker cosmological background. We present a careful stability analysis of asymptotic fixed points. We find that the traditional fixed point cannot be approached dynamically, except from a perfectly fine-tuned initial condition involving both the quasidilaton and the Hubble parameter. A less-well examined fixed- point solution, where the time derivative of the zeroth Stückelberg field vanishes φ_ 0 1⁄4 0, encounters no such difficulty, and the fixed point is an attractor in some finite region of initial conditions. We examine the question of the presence of a Boulware-Deser ghost in the theory. We show that the additional constraint that generically allows for the elimination of the Boulware-Deser mode is only present under special initial conditions. We find that the only possibility corresponds to the traditional fixed point and the initial conditions are the same fine-tuned conditions that allow the fixed point to be approached dynamically. |
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