New Ekpyrotic Cosmology
| dc.creator | Buchbinder, Evgeny I. | |
| dc.creator | Khoury, Justin | |
| dc.creator | Ovrut, Burt A. | |
| dc.date | 2007-02-20 | |
| dc.date | 2007-11-22 | |
| dc.date.accessioned | 2026-07-07T11:23:39Z | |
| dc.date.available | 2026-07-07T11:23:39Z | |
| dc.description | In this paper, we present a new scenario of the early Universe that contains a pre big bang Ekpyrotic phase. By combining this with a ghost condensate, the theory explicitly violates the null energy condition without developing any ghost-like instabilities. Thus the contracting universe goes through a non-singular bounce and evolves smoothly into the expanding post big bang phase. The curvature perturbation acquires a scale-invariant spectrum well before the bounce in this scenario. It is sourced by the scale-invariant entropy perturbation engendered by two ekpyrotic scalar fields, a mechanism recently proposed by Lehners et al. Since the background geometry is non-singular at all times, the curvature perturbation remains nearly constant on super horizon scales. It emerges from the bounce unscathed and imprints a scale-invariant spectrum of density fluctuations in the matter-radiation fluid at the onset of the hot big bang phase. The ekpyrotic potential can be chosen so that the spectrum has a ``red'' tilt, in accordance with the recent data from WMAP. As in the original Ekpyrotic scenario, the model predicts a negligible gravity wave signal on all observable scales. As such ``New Ekpyrotic Cosmology" provides a consistent and distinguishable alternative to inflation to account for the origin of the seeds of large scale structure. | |
| dc.description | 41 pages, 4 figures. v2: minor corrections, references added. v3: small modifications in bounce section, references added. v4: version published in PRD | |
| dc.identifier | https://arxiv.org/abs/hep-th/0702154 | |
| dc.identifier | http://arxiv.org/abs/hep-th/0702154 | |
| dc.identifier | Phys.Rev.D76:123503,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.123503 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/194964 | |
| dc.subject | High Energy Physics - Theory | |
| dc.subject | Astrophysics | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | New Ekpyrotic Cosmology | |
| dc.type | text |