The time evolution of a higher-dimensional universe with a topology of R×Sd×SD is discussed by using the effective action in a high-temperature limit. The universe, which starts at high temperature, always comes out of thermal equilibrium. Consequently, nonthermal quantum effects such as particle production become very important. The conversion from gravitational entropy to matter entropy through particle production might give the present large entropy.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)