431 citations · 3k across the 56 of their papers we have counts for
56 papers
Axion-Like Particles and Recent Observations of the Cosmic Infrared Background Radiation
Kazunori Kohri, Hideo Kodama
The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength 1 m c…
Bosenova and Axiverse
Hirotaka Yoshino, Hideo Kodama
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 rotat…
Inflation in maximal gauged supergravities
Hideo Kodama, Masato Nozawa
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 frame…
Probing the string axiverse by gravitational waves from Cygnus X-1
Hirotaka Yoshino, Hideo Kodama
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…
Stability of the Schwarzschild-de Sitter black hole in the dRGT massive gravity theory
Hideo Kodama, Ivan Arraut
The Schwarzschild-de Sitter solution in the Einstein theory with a positive cosmological constant becomes an exact solution to the dRGT non-linear massive gravity theory…
Gravitational radiation from an axion cloud around a black hole: Superradiant phase
Hirotaka Yoshino, Hideo Kodama
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 ext…