Vainshtein mechanism in Gauss-Bonnet gravity and Galileon aether
Keywords: dimensional reduction, gauss-bonnet, Galileons
Abstract
We derive field equations of Gauss-Bonnet gravity in four dimensions after dimensional reduction of the action and demonstrate that in this scenario the Vainshtein mechanism operates in the flat spherically symmetric background. We show that inside this Vainshtein sphere the fifth force is negligibly small compared to the gravitational force. We also investigate the stability of the spherically symmetric solution, and clarify the vocabulary used in the literature about the hyperbolicity of the equation and the ghost-Laplacian stability conditions. We find superluminal behavior of the perturbation of the field in the radial direction. However, because of the presence of the nonlinear terms, the structure of the space-time is modified and as a result the field does not propagate in the Minkowski metric but rather in an aether composed of the scalar field pi(r). We thereby demonstrate that the superluminal behavior does not create time paradoxes thanks to the absence of causal closed curves. We also derive the stability conditions for a Friedmann universe in context with scalar and tensor perturbations and we study the cosmology of the model.
Más información
Título según WOS: | Vainshtein mechanism in Gauss-Bonnet gravity and Galileon aether |
Título de la Revista: | PHYSICAL REVIEW D |
Volumen: | 85 |
Número: | 2 |
Editorial: | AMER PHYSICAL SOC |
Fecha de publicación: | 2012 |
Idioma: | English |
URL: | http://link.aps.org/doi/10.1103/PhysRevD.85.024019 |
DOI: |
10.1103/PhysRevD.85.024019 |
Notas: | ISI |