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(s) organisatrice(s) / Organizing team(s):
- Théorie