Séminaire / Seminar GReCO |
| « Towards a classification of higher derivative scalar-tensor theorie » |
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K. Noui |
| Theories with higher order time derivatives in the Lagrangian generically suffer from ghost-like instabilities, known as Ostrogradski instabilities. Nonetheless, in some situations, this fate can be avoided and the Ostrogradski ghost does not exist. This is the case for Horndeski theories which are scalar-tensor theories, candidates for an alternative explanation of dark energy. However, there are not the only "safe" higher-derivative scalar-tensor theories. In this talk, I will present a way to classify ghost-free scalar tensor theories, focussing mainly on theories that depend quadratically on the second derivatives of a scalar field. This talk is based on works in collaboration with D.Langlois. |
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lundi 18 janvier 2016 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |