Waseda University

output

19922026

most citedObservation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

10.9k citations

researchers with a paper here

Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.

collaborating institutions

Showing 2022 · gr-qcShow all

18 papers · 2 filters

gr-qc2022★ 18 cited

Consistency of matter coupling in modified gravity

Kazufumi Takahashi, Rampei Kimura, Hayato Motohashi

Matter coupling in modified gravity theories is a nontrivial issue when the gravitational Lagrangian possesses a degeneracy structure to avoid the problem of the Ostrogradsky ghost…

gr-qc2022★ 14 cited

Cosmological stability in $f (ϕ, G)$ gravity

Shinji Tsujikawa

In gravitational theories where a canonical scalar field $ϕ$ with a potential $V (ϕ)$ is coupled to a Gauss-Bonnet (GB) term $G$ with the Lagrangian $f (ϕ, G)$ , we study…

gr-qc2022★ 22 cited

Spin-2 dark matter from anisotropic Universe in bigravity

Yusuke Manita, Katsuki Aoki, Tomohiro Fujita +1

Bigravity is one of the natural extensions of general relativity and contains an additional massive spin-2 field which can be a good candidate for dark matter. To discuss the produ…

gr-qc2022★ 7 cited

Gravitational collapse and formation of a black hole in a type II minimally modified gravity theory

Antonio De Felice, Kei-ichi Maeda, Shinji Mukohyama +1

We study the spherically symmetric collapse of a cloud of dust in VCDM, a class of gravitational theories with two local physical degrees of freedom. We find that the collapse corr…

gr-qc2022★ 5 cited

How does SU( $N$ )-natural inflation isotropize the universe?

Tomoaki Murata, Tomohiro Fujita, Tsutomu Kobayashi

We study the homogeneous and anisotropic dynamics of pseudoscalar inflation coupled to an SU( $N$ ) gauge field. To see how the initially anisotropic universe is isotropized in such…

gr-qc2022★ 4 cited

Cosmology in theories with spontaneous scalarization of neutron stars

Ratchaphat Nakarachinda, Sirachak Panpanich, Shinji Tsujikawa +1

In a model of spontaneous scalarization of neutron stars proposed by Damour and Esposite-Farese, a general relativistic branch becomes unstable to trigger tachyonic growth of a sca…

gr-qc2022★ 25 cited

Inspiral gravitational waveforms from compact binary systems in Horndeski gravity

Yurika Higashino, Shinji Tsujikawa

In a subclass of Horndeski theories with the speed of gravity equivalent to that of light, we study gravitational radiation emitted during the inspiral phase of compact binary syst…

gr-qc2022★ 3 cited

Symmetry restoration in the vicinity of neutron stars with a nonminimal coupling

Masato Minamitsuji, Shinji Tsujikawa

We propose a new model of scalarized neutron stars (NSs) realized by a self-interacting scalar field $ϕ$ nonminimally coupled to the Ricci scalar $R$ of the form $F (ϕ) R$ . The scala…

gr-qc2022★ 23 cited

Hamiltonian formulation and loop quantization of a recent extension of the Kruskal spacetime

Beatriz Elizaga Navascués, Alejandro García-Quismondo, Guillermo A. Mena Marugán

We study the Hamiltonian formulation of the Ashtekar-Olmedo-Singh model for the description of the interior geometry of non-rotating, uncharged black holes. This model incorporates…

gr-qc2022★ 8 cited

Stability of neutron stars in Horndeski theories with Gauss-Bonnet couplings

Masato Minamitsuji, Shinji Tsujikawa

In Horndeski theories containing a scalar coupling with the Gauss-Bonnet (GB) curvature invariant $R_{GB}^{2}$ , we study the existence and linear stability of neutron star (NS) s…

gr-qc2022★ 11 cited

Space of solutions of the Ashtekar-Olmedo-Singh effective black hole model

Beatriz Elizaga Navascués, Alejandro García-Quismondo, Guillermo A. Mena Marugán

We consider a general choice of integration constants in the resolution of the dynamical equations derived from a recently proposed effective model that describes black hole spacet…

gr-qc2022★ 2 cited

On the stability of covariant BSSN formulation

Ryosuke Urakawa, Takuya Tsuchiya, Gen Yoneda

In this study, we investigate the numerical stability of the covariant BSSN (cBSSN) formulation proposed by Brown. We calculate the constraint amplification factor (CAF), which is…

gr-qc2022★ 12 cited

Instability of hairy black holes in regularized 4-dimensional Einstein-Gauss-Bonnet gravity

Shinji Tsujikawa

In regularized 4-dimensional Einstein-Gauss-Bonnet (EGB) gravity derived from a Kaluza-Klein reduction of higher-dimensional EGB theory, we study the existence and stability of bla…

gr-qc2022★ 26 cited

Linear stability of black holes with static scalar hair in full Horndeski theories: generic instabilities and surviving models

Masato Minamitsuji, Kazufumi Takahashi, Shinji Tsujikawa

In full Horndeski theories, we show that the static and spherically symmetric black hole (BH) solutions with a static scalar field~ $ϕ$ whose kinetic term~ $X$ is nonvanishing on the…

gr-qc2022★ 27 cited

VCDM and Cuscuton

Antonio De Felice, Kei-ichi Maeda, Shinji Mukohyama +1

We investigate two Type-IIa Minimally Modified Gravity theories, namely VCDM and Cuscuton theories. We confirm that all acceptable Cuscuton solutions are always solutions for VCDM…

gr-qc2022

Stable numerical simulation of Einstein equations in gravitational collapse space--time

Takuya Tsuchiya, Ryosuke Urakawa, Gen Yoneda

We perform simulations in a gravitational collapsing model using the Einstein equations. In this paper, we review the equations for constructing the initial values and the evolutio…

gr-qc2022★ 16 cited

Cuscuta-Galileon cosmology: Dynamics, gravitational "constant"s and the Hubble Constant

Kei-ichi Maeda, Sirachak Panpanich

We discuss cosmology based on a Cuscuta-Galileon gravity theory, which preserves just two degrees of freedom. Although there exists no additional degrees of freedom, introduction o…

gr-qc2022★ 29 cited

Linear stability of black holes in shift-symmetric Horndeski theories with a time-independent scalar field