29 citations · 107 across the 8 of their papers we have counts for
8 papers
Galaxy Distributions and Tsallis Statistical Mechanics
Akika Nakamichi, Izumi Joichi, Osamu Iguchi +1
Large-scale astrophysical systems are non-extensive due to their long-range force of gravity. Here we show an approach toward the statistical mechanics of such self-gravitating sys…
Composability and Generalized Entropy
M. Hotta, I. Joichi
We address in this paper how tightly the composability nature of systems: constrains definition of generalized entropies and investigate explicitly the compo…
Prolonged Decay and CP-asymmetry
I. Joichi, Sh. Matsumoto, M. Yoshimura
Time evolution of unstable particles that occur in the expanding universe is investigated. The off-shell effect not included in the Boltzmann-like equation is important for the dec…
Quantum Dissipation in Open Harmonic Systems: Operator Solution
I. Joichi, Sh. Matsumoto, M. Yoshimura
A finite number of harmonic oscillators coupled to infinitely many environment oscillators is fundamental to the problem of understanding quantum dissipation of a small system imme…
High Momentum Behavior of Geometric Bremsstrahlung in the Expanding Universe
M. Hotta, H. Inoue, I. Joichi +1
We shall discuss various kinds of geometric bremsstrahlung processes in the spatially flat Robertson-Walker universe. Despite that the temperature of the universe is much higher th…
Quantum Dissipation and Decay in Medium
I. Joichi, Sh. Matsumoto, M. Yoshimura
Quantum dissipation in thermal environment is investigated, using the path integral approach. The reduced density matrix of the harmonic oscillator system coupled to thermal bath o…