Extended Cuscuton: Formulation and Cosmology

Among single-field scalar-tensor theories, there is a special class called "cuscuton,"
which is represented as general relativity with a noncanonical scalar field. This theory
has a remarkable feature that scalar perturbations do not propagate on a cosmological
background. We specify a subclass of the (beyond) Horndeski class having this
property and thus extend the framework of cuscuton. We also discuss the stability of
cosmological perturbations in the extended cuscuton models.

Dates: 

Mardi, 10 juillet, 2018 - 14:00

Salle / Local: 

483 A - Malevitch

Nom/Prénom // Last name/First name: 

Kazufumi Takahashi

Affiliation: 

RESCEU Tokyo

Equipe organisatrice / Organizing team: 

  • Théorie