117 citations · 1k across the 40 of their papers we have counts for
3 papers · 2 filters
Gravitational scalar-tensor theory
Atsushi Naruko, Daisuke Yoshida, Shinji Mukohyama
We consider a new form of theories of gravity in which the action is written in terms of the Ricci scalar and its first and second derivatives. Despite the higher derivative nature…
Cosmological disformal invariance
Guillem Domènech, Atsushi Naruko, Misao Sasaki
The invariance of physical observables under disformal transformations is considered. It is known that conformal transformations leave physical observables invariant. However, whet…
Multi-disformal invariance of nonlinear primordial perturbations
Yuki Watanabe, Atsushi Naruko, Misao Sasaki
We study disformal transformations of the metric in the cosmological context. We first consider the disformal transformation generated by a scalar field and show that the curva…