214 citations · 721 across the 14 of their papers we have counts for
8 papers · 1 filter
Generalising the matter coupling in massive gravity: a search for new interactions
A. Emir Gumrukcuoglu, Kazuya Koyama
Massive gravity theory introduced by de Rham, Gabadadze, Tolley (dRGT) is restricted by several uniqueness theorems that protect the form of the potential and kinetic terms, as wel…
Role of matter in extended quasidilaton massive gravity
A. Emir Gumrukcuoglu, Kazuya Koyama, Shinji Mukohyama
The extended quasidilaton theory is one of the simplest Lorentz-invariant massive gravity theories which can accommodate a stable self-accelerating vacuum solution. In this paper w…
Jeans' Ghost
A. Emir Gumrukcuoglu, Shinji Mukohyama, Thomas P. Sotiriou
We show that a massless canonical scalar field minimally coupled to general relativity can become a tachyonic ghost at low energies around a background in which the scalar's gradie…
Viable cosmology in bimetric theory
Antonio De Felice, A. Emir Gumrukcuoglu, Shinji Mukohyama +2
We study cosmological perturbations in bimetric theory with two fluids each of which is coupled to one of the two metrics. Focusing on a healthy branch of background solutions, we…
Open FRW universes and self-acceleration from nonlinear massive gravity
A. Emir Gumrukcuoglu, Chunshan Lin, Shinji Mukohyama
In the context of a recently proposed nonlinear massive gravity with Lorentz-invariant mass terms, we investigate open Friedmann-Robertson-Walker (FRW) universes driven by arbitrar…
General relativity limit of Horava-Lifshitz gravity with a scalar field in gradient expansion
A. Emir Gumrukcuoglu, Shinji Mukohyama, Anzhong Wang
We present a fully nonlinear study of long wavelength cosmological perturbations within the framework of the projectable Horava-Lifshitz gravity, coupled to a single scalar field.…