Zobrazeno 1 - 10
of 174
pro vyhledávání: '"Kodama, Hideo"'
Autor:
Kohri, Kazunori, Kodama, Hideo
Publikováno v:
Phys. Rev. D 96, 051701 (2017)
The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength $\sim$ 1 $\mu$m compared to theoretically-inferred values. The amount of the CIB radi
Externí odkaz:
http://arxiv.org/abs/1704.05189
Autor:
Yoshino, Hirotaka, Kodama, Hideo
Publikováno v:
Class. Quantum Grav. 32 (2015) 214001
We report some new interesting features of the dynamics of a string axion field (i.e., a (pseudo-)scalar field with tiny mass with sine-Gordon-type self-interaction) around a rotating black hole in three respects. First, we revisit the calculation of
Externí odkaz:
http://arxiv.org/abs/1505.00714
Autor:
Kodama, Hideo, Nozawa, Masato
Publikováno v:
JCAP 1505 (2015) 05, 028
We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of ${\rm SO}(4,4)$
Externí odkaz:
http://arxiv.org/abs/1502.01378
Autor:
Yoshino, Hirotaka, Kodama, Hideo
Publikováno v:
Prog. Theor. Exp. Phys. (2015) 061E01
In the axiverse scenario, a massive scalar field (string axion) forms a cloud around a rotating black hole (BH) by superradiant instability and emits continuous gravitational waves (GWs). We examine constraints on the string axion parameters that can
Externí odkaz:
http://arxiv.org/abs/1407.2030
Autor:
Yoshino, Hirotaka, Kodama, Hideo
Publikováno v:
Prog. Theor. Exp. Phys. (2014) 043E02
Motivated by possible existence of string axions with ultralight masses, we study gravitational radiation from an axion cloud around a rotating black hole (BH). The axion cloud extracts the rotation energy of the BH by superradiant instability, while
Externí odkaz:
http://arxiv.org/abs/1312.2326
Autor:
Kodama, Hideo, Arraut, Ivan
Publikováno v:
Prog. Theor. Exp. Phys. (2014) 023E02
The Schwarzschild-de Sitter solution in the Einstein theory with a positive cosmological constant $\Lambda=m^2/\alpha$ becomes an exact solution to the dRGT non-linear massive gravity theory with the mass parameter $m$ when the theory parameters $\al
Externí odkaz:
http://arxiv.org/abs/1312.0370
Autor:
Kodama, Hideo, Nozawa, Masato
This article presents a systematic study of critical points for the SL(8, R)-type gauging in four dimensional maximal gauged supergravity. We determine all the possible vacua for which the origin of the moduli space becomes a critical point. We formu
Externí odkaz:
http://arxiv.org/abs/1210.4238
Publikováno v:
Phys. Rev. D 89, 044016 (2014)
Black objects lose their mass and angular momenta through evaporation by Hawking radiation, and the investigation of their time evolution has a long history. In this paper, we study this problem for a five-dimensional doubly spinning black ring. The
Externí odkaz:
http://arxiv.org/abs/1205.5715
Autor:
Yoshino, Hirotaka, Kodama, Hideo
Publikováno v:
Prog. Theor. Phys. 128 (2012), 153-190
Motivated by possible existence of stringy axions with ultralight mass, we study the behavior of an axion field around a rapidly rotating black hole (BH) obeying the sine-Gordon equation by numerical simulations. Due to superradiant instability, the
Externí odkaz:
http://arxiv.org/abs/1203.5070
Autor:
Kodama, Hideo, Yoshino, Hirotaka
String theory/M-theory generally predicts that axionic fields with a broad mass spectrum extending below 10^{-10}eV are produced after compactification to four dimensions. These axions/fields provoke a rich variety of cosmophysical phenomena on diffe
Externí odkaz:
http://arxiv.org/abs/1108.1365