24 citations · 79 across the 8 of their papers we have counts for
8 papers
Gravitational Wave Gastronomy
David I. Dunsky, Anish Ghoshal, Hitoshi Murayama +2
The symmetry breaking of grand unified gauge groups in the early Universe often leaves behind relic topological defects such as cosmic strings, domain walls, or monopoles. For some…
Theories with limited extrinsic curvature and a nonsingular anisotropic universe
Yuki Sakakihara, Daisuke Yoshida, Kazufumi Takahashi +1
We propose a class of theories that can limit scalars constructed from the extrinsic curvature. Applied to cosmology, this framework allows us to control not only the Hubble parame…
Accelerating Universe with a stable extra dimension in cuscuton gravity
Asuka Ito, Yuki Sakakihara, Jiro Soda
We study Kaluza-Klein cosmology in cuscuton gravity and find an exact solution describing an accelerating 4-dimensional universe with a stable extra dimension. A cuscuton which is…
Ghost-free scalar-fermion interactions
Rampei Kimura, Yuki Sakakihara, Masahide Yamaguchi
We discuss a covariant extension of interactions between scalar fields and fermions in a flat space-time. We show, in a covariant theory, how to evade fermionic ghosts appearing be…
Ghost free boson-fermion co-existence system
Rampei Kimura, Yuki Sakakihara, Masahide Yamaguchi
We study co-existence system of both bosonic and fermionic degrees of freedom. For such system with up to first derivatives in Lagrangian, we find Ostrogradsky-type ghost-free cond…
Primordial fluctuations from inflation in dRGT bimetric theory of gravity
Yuki Sakakihara, Takahiro Tanaka
We investigate primordial gravitational waves and curvature perturbations in de Rham-Gabadadze-Tolley (dRGT) bimetric gravity. We evaluate the power-spectra in the leading order in…
Primordial Gravitational Waves in Bimetric Gravity
Yuki Sakakihara, Jiro Soda
We study primordial tensor power-spectra generated during inflation in bimetric gravity. More precisely, we examine a homogeneous expanding spacetime in a minimal bimetric model wi…
On Cosmic No-hair in Bimetric Gravity and the Higuchi Bound
Yuki Sakakihara, Jiro Soda, Tomohiro Takahashi
We study the cosmic no-hair in the presence of spin-2 matter, i.e. in bimetric gravity. We obtain stable de Sitter solutions with the cosmological constant in the physical sector a…