Attractor scenarios and superluminal signals in k-essence cosmology
| dc.creator | Kang, Jin U | |
| dc.creator | Vanchurin, Vitaly | |
| dc.creator | Winitzki, Sergei | |
| dc.date | 2007-06-27 | |
| dc.date | 2007-06-28 | |
| dc.date.accessioned | 2026-07-07T10:56:28Z | |
| dc.date.available | 2026-07-07T10:56:28Z | |
| dc.description | Cosmological scenarios with k-essence are invoked in order to explain the observed late-time acceleration of the universe. These scenarios avoid the need for fine-tuned initial conditions (the "coincidence problem") because of the attractor-like dynamics of the k-essence field ϕ. It was recently shown that all k-essence scenarios with Lagrangians p=L(X)/ϕ^2, necessarily involve an epoch where perturbations of ϕpropagate faster than light (the "no-go theorem"). We carry out a comprehensive study of attractor-like cosmological solutions ("trackers") involving a k-essence scalar field ϕand another matter component. The result of this study is a complete classification of k-essence Lagrangians that admit asymptotically stable tracking solutions, among all Lagrangians of the form p=K(ϕ)L(X) . Using this classification, we select the class of models that describe the late-time acceleration and avoid the coincidence problem through the tracking mechanism. An analogous "no-go theorem" still holds for this class of models, indicating the existence of a superluminal epoch. In the context of k-essence cosmology, the superluminal epoch does not lead to causality violations. We discuss the implications of superluminal signal propagation for possible causality violations in Lorentz-invariant field theories. | |
| dc.description | 27 pages, RevTeX4. Minor cosmetic changes, references added | |
| dc.identifier | https://arxiv.org/abs/0706.3994 | |
| dc.identifier | http://arxiv.org/abs/0706.3994 | |
| dc.identifier | Phys.Rev.D76:083511,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.083511 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/186425 | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | Astrophysics | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Attractor scenarios and superluminal signals in k-essence cosmology | |
| dc.type | text |