Early reionization by decaying particles and cosmic microwave background radiation (2004)
We study the reionization scenario in which ionizing UV photons emitted from decaying particle, in addition to usual contributions from stars and quasars, ionize the universe. It is found that the...
Partially ionizing the universe by decaying particles (2003)
Kasuya, S., Kawasaki, M., Sugiyama, Naoshi
We show that UV photons produced by decaying particles can partially reionize the universe and explain the large optical depth observed by Wilkinson Microwave Anisotropy Probe. Together with UV...
MSSM curvaton in the gauge-mediated SUSY breaking (2003)
Kasuya, S., Kawasaki, M., Takahashi, Fuminobu
We study the curvaton scenario using the MSSM flat directions in the gauge-mediated SUSY breaking model. We find that the fluctuations in the both radial and phase directions can be responsible for...
Affleck-Dine mechanism with negative thermal logarithmic potential (2003)
Kasuya, S., Kawasaki, M., Takahashi, Fuminobu
We investigate whether the Affleck-Dine (AD) mechanism works when the contribution of the two-loop thermal correction to the potential is negative in the gauge-mediated supersymmetry breaking models....
Kasuya, S., Kawasaki, M., Takahashi, Fuminobu
We find that there exists a soliton-like solution ``I-ball'' in theories of a real scalar field if the scalar potential satisfies appropriate conditions. Although the I-ball does not have any...
Affleck-Dine baryogenesis and the Q-ball dark matter in the gauge-mediated SUSY breaking (2002)
We consider the Affleck-Dine baryogenesis comprehensively in the minimal supersymmetric standard model with gauge-mediated supersymmetry breaking. Considering the high temperature effects, we see...
On the Moduli Problem and Baryogenesis in Gauge-mediated SUSY Breaking Models (2001)
Kasuya, S., Kawasaki, M., Takahashi, Fuminobu
We investigate whether the Affleck-Dine mechanism can produce sufficient baryon number of the universe in the gauge-mediated SUSY breaking models, while evading the cosmological moduli problem by...
Q-ball formation: Obstacle to Affleck-Dine baryogenesis in the gauge-mediated SUSY breaking ? (2001)
We consider the Affleck-Dine baryogenesis comprehensively in the minimal supersymmetric standard model with gauge-mediated supersymmetry breaking. Considering the high temperature effects, we see...
Difficulty of a spinning complex scalar field to be dark energy (2001)
We comment on the possibility of a spinning complex scalar field to be dark energy. We show that it deforms (almost) completely into a nontopological soliton state, a Q ball, and the equation of...
New type of stable Q balls in the gauge-mediated supersymmetry breaking (2000)
We obtain a new type of a stable Q ball in the context of gauge-mediated supersymmetry breaking in minimal supersymmetric standard model. It is so-called gravity-mediation type of Q ball, but stable...
Q-ball formation in the gravity-mediated SUSY breaking scenario (2000)
We study the formation of Q-balls which are made of flat directions that appear in the supersymmetric extension of the standard model in the context of gravity-mediated supersymmetry breaking. The...
Q-ball Formation through Affleck-Dine Mechanism (1999)
We present the full nonlinear calculation of the formation of a Q-ball through the Affleck-Dine (AD) mechanism by numerical simulations. It is shown that large Q-balls are actually produced by the...
Remarks on Cosmic String Formation during Preheating on Lattice Simulations (1999)
We reconsider the formation of (global) cosmic strings during and after preheating by calculating the dynamics of a scalar field on both two- and three- dimensional lattices. We have found that there...
Topological Defects Formation after Inflation on Lattice Simulation (1998)
We consider the formation of topological defects after inflation. In order to take into account the effects of the rescattering of fluctuations, we integrate the classical equation that describes the...
Domain Wall Problem of Axion and Isocurvature Fluctuations in Chaotic Inflation Models (1997)
Kasuya, S., Kawasaki, M., Yanagida, T.
We study the domain wall problem of an axion in chaotic inflation models. We show that the production of domain walls does not occurs if the Peccei-Quinn scalar has a flat potential and its breaking...
Can topological defects be formed during preheating ? (1997)
We study the dynamics of a scalar field \Phi with the potential g(|\Phi|^2-\eta^2)^2/2 (g=self-coupling constant, \eta=symmetry breaking scale) after inflation and make clear whether topological...
Cosmological Axion Problem in Chaotic Inflationary Universe (1996)
Kasuya, S., Kawasaki, M., Yanagida, T.
We investigate two cosmological axion problems (isocurvature fluctuations and domain-wall formation) in chaotic inflationary universe. It is believed that these problems are solved if potential for...
Apoptosis of lymphocytes in mice induced by infection with Rickettsia tsutsugamushi.
Kasuya, S, Nagano, I, Ikeda, T, Goto, C, Shimokawa, K, Takahashi, Y
Histological examinations of mice infected with either a lethal (Karp) or a self-limitating (Gilliam) strain of Rickettsia tsutsugamushi were performed. Tingible body macrophages in the spleen and...
Yamashita, T, Kasuya, S, Noda, N, Nagano, I, Kang, J S
Thirty-two newly isolated strains of Rickettsia tsutsugamushi, 14 from patients with tsutsugamushi disease, 12 from wild rodents, and 6 from trombiculid mites parasitizing rodents in Gifu Prefecture,...
Yamashita, T, Kasuya, S, Noda, S, Nagano, I, Ohtsuka, S, Ohtomo, H
Four isolated strains of Rickettsia tsutsugamushi from patients in a new endemic area of Japan were tested for antigenicities by using 12 monoclonal antibodies to Karp, Gilliam, and Kato strains. It...
Apoptosis of lymphocytes in mice induced by infection with Rickettsia tsutsugamushi.
Kasuya, S, Nagano, I, Ikeda, T, Goto, C, Shimokawa, K, Takahashi, Y
Histological examinations of mice infected with either a lethal (Karp) or a self-limitating (Gilliam) strain of Rickettsia tsutsugamushi were performed. Tingible body macrophages in the spleen and...
Yamashita, T, Kasuya, S, Noda, N, Nagano, I, Kang, J S
Thirty-two newly isolated strains of Rickettsia tsutsugamushi, 14 from patients with tsutsugamushi disease, 12 from wild rodents, and 6 from trombiculid mites parasitizing rodents in Gifu Prefecture,...
Yamashita, T, Kasuya, S, Noda, S, Nagano, I, Ohtsuka, S, Ohtomo, H
Four isolated strains of Rickettsia tsutsugamushi from patients in a new endemic area of Japan were tested for antigenicities by using 12 monoclonal antibodies to Karp, Gilliam, and Kato strains. It...