139 citations · 480 across the 19 of their papers we have counts for
19 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…
Phantom crossing dark energy in Horndeski's theory
Jiro Matsumoto
The CDM model is a remarkably successful model which is consistent with the observations of cosmic microwave background radiation (CMB), baryon acoustic oscillation (BAO), and l…
General dynamical properties of cosmological models with nonminimal kinetic coupling
Jiro Matsumoto, Sergey V. Sushkov
We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as , where i…
Unified description of dark energy and dark matter in mimetic matter model
Jiro Matsumoto
The existence of dark matter and dark energy in cosmology is implied by various observations, however, they are still unclear because they have not been directly detected. In this…
Scalar field dark energy with a minimal coupling in a spherically symmetric background
Jiro Matsumoto
Dark energy models and modified gravity theories have been actively studied and the behaviors in the solar system have been also carefully investigated in a part of the models. How…
Cosmology with nonminimal kinetic coupling and a Higgs-like potential
Jiro Matsumoto, Sergey V. Sushkov
We consider cosmological dynamics in the theory of gravity with the scalar field possessing the nonminimal kinetic coupling to curvature given as , and the Hig…
Cosmological perturbations in mimetic matter model
Jiro Matsumoto, Sergei D. Odintsov, Sergey V. Sushkov
We investigate the cosmological evolution of mimetic matter model with arbitrary scalar potential. The cosmological reconstruction, which is the way to construct a model for arbitr…
Cosmological perturbations in the models of dark energy and modified gravity
Jiro Matsumoto
The quasi-static solutions of the matter density perturbation in various dark energy models and modified gravity models have been investigated in numerous papers. However, the osci…
Black Hole Firewalls Require Huge Energy of Measurement
Masahiro Hotta, Jiro Matsumoto, Ken Funo
The unitary moving mirror model is one of the best quantum systems for checking the reasoning of the original firewall paradox of AMPS in quantum black holes. Though the late-time…
Cosmological perturbations in gravity
Jiro Matsumoto
The quasi-static solutions of the matter density perturbation in gravity models have been investigated in numerous papers. However, the oscillating solutions in gravi…
Quantum Energy Teleportation without Limit of Distance
Masahiro Hotta, Jiro Matsumoto, Go Yusa
Quantum energy teleportation (QET) is, from an operational viewpoint of distant protocol users, the transportation of energy via local operations and classical communication. QET h…
The Casimir effect as a candidate of dark energy
Jiro Matsumoto
It is known that the simply evaluated value of the zero point energy of quantum fields is extremely deviated from the observed value of dark energy density. In this paper, we consi…
Generalized Galileon Model -- cosmological reconstruction and the Vainshtein mechanism --
Norihito Shirai, Kazuharu Bamba, Shota Kumekawa +2
Explicit formulae of the equations in the generalized Galileon models are given. We also develop the formulation of the reconstruction. By using the formulation, we can explicitly…
Cosmological perturbations in -essence model
Kazuharu Bamba, Jiro Matsumoto, Shin'ichi Nojiri
Subhorizon approximation is often used in cosmological perturbation theory. In this paper, however, it is shown that the subhorizon approximation is not always a good approximation…
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…
Dark energy from modified gravity with Lagrange multipliers
Salvatore Capozziello, Jiro Matsumoto, Shin'ichi Nojiri +1
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of…
Reconstruction of k-essence model
Jiro Matsumoto, Shin'ichi Nojiri
We explicitly construct the k-essence models which reproduce the arbitrary FRW cosmology, that is, the arbitrary time-development of the scale factor or the Hubble rate. The k-esse…