2015.8.6 updated
4/8(Wed)17:00- @3号館108谷崎佑弥
Lefschetz-thimble path integral for evading the sign problem (pdf)
Recently, Picard-Lefschetz theory attracts theoretical attention as a possible solution of the sign problem. The sign problem is originated from an oscillatory integration because it forbids us from using the important sampling of the Monte Carlo integration, and it also causes some disease in the mean-field approximation. In this seminar, I am planning to review theoretical minimal of the Picard-Lefschetz theory, and it will clearly tell how one can possibly solve the sign problem. After that, our recent study on the phase transition of a matrix model is explained, and we will see that how Lefschetz thimbles visualizes the idea of Lee-Yang theorem for zeros of the partition function. I would also like to tell that the sign problem in the mean-field approximation can be completely solved by using the Picard-Lefschetz theory.
13:00- @15号館104
13:00- @16号館126
Francois Gelis
(IPhT, Saclay)
Non-equilibrium quantum field theory in heavy ion collisions
In this talk, I discuss several approaches for the study of the out-of-equilibrium early stages of heavy ion collisions. Starting from the Schwinger-Keldysh formalism, I will show how to derive the classical statistical approximation (CSA) and the kinetic theory. In the CSA, several types of initial conditions can be used, that correspond to various forms of classical approximation, and I will discuss their respective advantages and problems. Finally, I will discuss some recent numerical results about the early stages of heavy ion collisions obtained using these techniques.

* 教室が1日目, 2日目で違うので注意してください。