Speaker
Prof.
Akira Ohnishi
(Kyoto University)
Description
Understanding the mechanisms causing rapid thermalization deduced for
high-energy heavy ion collisions is still a challenge.
Thermalization is not fast enough in perturbative esitmate,
and several instabilities in the classical Yang-Mills (CYM) equation
have been considered. In this work, we have evaluated the equilibration
time from the chaotic behavior of CYM [1]. We have developed a method to
evaluete intermediate Lyapunov exponents (ILEs) by integrating the equation
of motion for an intermediate time period. Sum of positive ILEs gives
the entropy production rate in intermediate times, and is found to follow
(energy density)^{1/4} as expected from the scale invariance of CYM.
As a phenomenological application we conclude that for pure gauge theories
with random initial conditions thermalization occures within few fm/c,
an estimate which can be reduced by the inclusion of fermions,
specific initial conditions etc.
[1] T. Kunihiro, B. Muller, A. Ohnishi, A. Schafer, T.T. Takahashi, A.
Yamamoto,Phys. Rev. D {\bf 82} (2010), 114015 [arXiv:1008.1156].
Author
Prof.
Akira Ohnishi
(Kyoto University)
Co-authors
Prof.
Andreas Schafer
(Regensburg University)
Dr
Arata Yamamoto
(University of Tokyo)
Prof.
Berndt Muller
(Duke University)
Prof.
Teiji Kunihiro
(Kyoto University)
Dr
Toru T. Takahashi
(Gunma National College of Technology)
