13-18 December 2015
International Conference Centre Geneva
Europe/Zurich timezone

Gravitational waves in a bigravity model: from inflation to present

16 Dec 2015, 16:55
Level 2, Room 14 (International Conference Centre Geneva)

Level 2, Room 14

International Conference Centre Geneva

17 Rue de Varembé, 1211 Geneva


Pietro Guarato (Université de Genève)


In this talk, a detailed analysis of the evolution of tensor perturbations in a cosmological background for a model of Hassan-Rosen theory of bigravity is presented. It is shown that gravitational waves are unstable in this setting, but also that in practice the amplitude of tensor perturbations generated during inflation is sufficiently suppressed to avoid this instability from showing up until today. Hence, this bigravity model cannot be excluded from a pure analysis of the tensor sector. However, stringent limits on inflation from vector and scalar perturbations are derived.

Primary author

Pietro Guarato (Université de Genève)


Giulia Cusin (University of Geneva) Mariele Motta (University of Geneva) Ruth Durrer (University of Geneva)

Presentation Materials