Ghost conditions for Gauss-Bonnet cosmologies
| dc.creator | Calcagni, Gianluca | |
| dc.creator | de Carlos, Beatriz | |
| dc.creator | De Felice, Antonio | |
| dc.date | 2006-04-27 | |
| dc.date | 2006-08-13 | |
| dc.date.accessioned | 2026-07-07T10:46:31Z | |
| dc.date.available | 2026-07-07T10:46:31Z | |
| dc.description | We investigate the stability against inhomogeneous perturbations and the appearance of ghost modes in Gauss-Bonnet gravitational theories with a non-minimally coupled scalar field, which can be regarded as either the dilaton or a compactification modulus in the context of string theory. Through cosmological linear perturbations we extract four no-ghost and two sub-luminal constraint equations, written in terms of background quantities, which must be satisfied for consistency. We also argue that, for a general action with quadratic Riemann invariants, homogeneous and inhomogeneous perturbations are, in general, inequivalent, and that attractors in the phase space can have ghosts. These results are then generalized to a two-field configuration. Single-field models as candidates for dark energy are explored numerically and severe bounds on the parameter space of initial conditions are placed. A number of cases proposed in the literature are tested and most of them are found to be unstable or observationally unviable. | |
| dc.description | 43 pages, 13 figures. Added references, corrected typos | |
| dc.identifier | https://arxiv.org/abs/hep-th/0604201 | |
| dc.identifier | http://arxiv.org/abs/hep-th/0604201 | |
| dc.identifier | Nucl.Phys.B752:404-438,2006 | |
| dc.identifier | doi:10.1016/j.nuclphysb.2006.06.020 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/183255 | |
| dc.subject | High Energy Physics - Theory | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.title | Ghost conditions for Gauss-Bonnet cosmologies | |
| dc.type | text |