Séminaire / Seminar GReCO |
| « Constructing degenerate higher-order theories » |
|
Hayato Motohashi |
| Scalar-tensor theories serve models for inflation and dark energy. Many efforts have been made recently for constructing the most general scalar-tensor theories with higher-order derivatives in their Lagrangian. Since higher-derivative theories are often associated with Ostrogradsky ghost which causes unbounded Hamiltonian, it is important to clarify how to evade it. In this talk, I will explain construction of healthy degenerate theories with higher-order derivatives which circumvent Ostrogradsky ghost. The method also allows us to construct ghost-free theories with derivatives higher than second order in Lagrangian. |
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lundi 18 juin 2018 - 11:00 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |