Brane inflation and the WMAP data: a Bayesian analysis
| dc.creator | Lorenz, Larissa | |
| dc.creator | Martin, Jerome | |
| dc.creator | Ringeval, Christophe | |
| dc.date | 2007-09-24 | |
| dc.date | 2008-07-24 | |
| dc.date.accessioned | 2026-07-07T11:37:27Z | |
| dc.date.available | 2026-07-07T11:37:27Z | |
| dc.description | The Wilkinson Microwave Anisotropy Probe (WMAP) constraints on string inspired ''brane inflation'' are investigated. Here, the inflaton field is interpreted as the distance between two branes placed in a flux-enriched background geometry and has a Dirac-Born-Infeld (DBI) kinetic term. Our method relies on an exact numerical integration of the inflationary power spectra coupled to a Markov-Chain Monte-Carlo exploration of the parameter space. This analysis is valid for any perturbative value of the string coupling constant and of the string length, and includes a phenomenological modelling of the reheating era to describe the post-inflationary evolution. It is found that the data favour a scenario where inflation stops by violation of the slow-roll conditions well before brane annihilation, rather than by tachyonic instability. Concerning the background geometry, it is established that log(v) > -10 at 95% confidence level (CL), where "v" is the dimensionless ratio of the five-dimensional sub-manifold at the base of the six-dimensional warped conifold geometry to the volume of the unit five-sphere. The reheating energy scale remains poorly constrained, Treh > 20 GeV at 95% CL, for an extreme equation of state (wreh ~ -1/3) only. Assuming the string length is known, the favoured values of the string coupling and of the Ramond-Ramond total background charge appear to be correlated. Finally, the stochastic regime (without and with volume effects) is studied using a perturbative treatment of the Langevin equation. The validity of such an approximate scheme is discussed and shown to be too limited for a full characterisation of the quantum effects. | |
| dc.description | 65 pages, 15 figures, uses iopart. Shortened version, updated references. Matches publication up to appendix B kept on the arXiv | |
| dc.identifier | https://arxiv.org/abs/0709.3758 | |
| dc.identifier | http://arxiv.org/abs/0709.3758 | |
| dc.identifier | JCAP0804:001,2008 | |
| dc.identifier | doi:10.1088/1475-7516/2008/04/001 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/199208 | |
| dc.subject | High Energy Physics - Theory | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Brane inflation and the WMAP data: a Bayesian analysis | |
| dc.type | text |