96 citations · 178 across the 5 of their papers we have counts for
5 papers
Distinguishing modified gravity with just two tensorial degrees of freedom from general relativity: Black holes, cosmology, and matter coupling
Aya Iyonaga, Tsutomu Kobayashi
We consider spatially covariant modified gravity in which the would-be scalar degree of freedom is made non-dynamical and hence there are just two tensorial degrees of freedom, i.e…
Stars disformally coupled to a shift-symmetric scalar field
Tact Ikeda, Aya Iyonaga, Tsutomu Kobayashi
We investigate static and spherically symmetric stars disformally coupled to a scalar field. The scalar field is assumed to be shift symmetric, and hence the conformal and disforma…
Extended Cuscuton as Dark Energy
Aya Iyonaga, Kazufumi Takahashi, Tsutomu Kobayashi
Late-time cosmology in the extended cuscuton theory is studied, in which gravity is modified while one still has no extra dynamical degrees of freedom other than two tensor modes.…
Dressed Power-law Inflation with Cuscuton
Asuka Ito, Aya Iyonaga, Suro Kim +1
We study dressed inflation with a cuscuton and find a novel exact power-law solution. It is well known that the conventional power-law inflation is inconsistent with the Planck dat…
Extended Cuscuton: Formulation
Aya Iyonaga, Kazufumi Takahashi, Tsutomu Kobayashi
Among single-field scalar-tensor theories, there is a special class called "cuscuton," which is represented as some limiting case of k-essence in general relativity. This theory ha…