9 citations · 13 across the 2 of their papers we have counts for
4 papers
New measures to test modified gravity cosmologies
Jiro Matsumoto, Teppei Okumura, Misao Sasaki
The observed accelerated expansion of the Universe may be explained by dark energy or the breakdown of general relativity (GR) on cosmological scales. When the latter case, a modif…
Inflationary spectral tilts as a result of the dilatation symmetry breaking
Pisin Chen, Jiro Matsumoto, Rio Saitou
We derive the spectral indices and their runnings of single inflation models by a new approach. We perform a dilatation transformation to the linear cosmological perturbations and…
Oscillating solutions of the matter density contrast in Horndeski's theory
Jiro Matsumoto
Evolution of the large scale structure of the Universe is described by galaxy bias and the growth rate function of the matter density contrast. The behavior of the growth rate func…
On the necessity of the revisions for the cosmological matter perturbations from the general relativity
Jiro Matsumoto
The differential equations, which are used for matter perturbations, are usually derived from the Newton gravity and the Euler equation in the expanded universe. In this paper, by…