Extended Cuscuton: Formulation and Cosmology

start date: 

Mardi, juillet 10, 2018 - 14:00


483 A - Malevitch


Kazufumi Takahashi

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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.