7 papers
Tunneling Phenomena in Cosmology: Some Fundamental Problems
M. Yoshimura
The fundamental problem of how tunneling in thermal medium is completed is addressed, and a new time scale of order 1/friction for its termination, which is usually much shorter th…
Quantum tunneling in thermal medium
Sh. Matsumoto, M. Yoshimura
Time evolution of tunneling phenomena in medium is studied using a standard model of environment interaction. A semiclassical formula valid at low, but finite temperatures is deriv…
Relic Abundance due to Cosmic Pair Annihilation
Sh. Matsumoto, M. Yoshimura
Pair annihilation of heavy stable particles that occurs in the early universe is reconsidered including the off-shell effect not properly taken into account by the conventional Bol…
Prolonged Decoupling
M. Yoshimura
We discuss decay of unstable particles and pair annihilation of stable heavy particles that occur in the cosmic medium, from the point of the fundamental microscopic theory. A full…
Elementarity in Open Systems - Unstable Particle Decay in Medium -
M. Yoshimura
The problem of unstable particle decay is discussed to show how elementarity of a subsystem immersed in an infinitely larger environment is lost. The decay law, when the same kind…
Elementary Processes in Dissipative Cosmic Medium
M. Yoshimura
Quantum dynamics of a finite degrees of freedom is often much affected by interaction with the larger environment of cosmic medium. In this lecture we first review some recent deve…