Time: 10:00am，May 7 (Thursday)

Location: Room 9409

Speaker: Dr. Syo Kamata, Rikkyo University

Title:Application of the Lefschets thimble HMC to the (0+1) dimensional Thirring model with finite density

Abstract:

High density QCD is one of the exciting topics in particle physics and nuclear physics. It is generally hard to calculate high density theory because of the sign problem, hence various approaches have been tried to solve this problem. In recent years, AuroraScience collaboration and Fujii et.al. proposed a new MC formulation called as Lefschetz thimble Monte Carlo. This formulation is based on Morse theory and is expected as an effective method to extract finite density physics. As a first step to finite density QCD, we investigated the (0+1) dimensional Thirring model with a chemical potential by using HMC simulation with the Lefschetz thimble formulation(LTH). Since this model can be solved exactly even on lattice space, we compared numerical results obtained by LTH with the exact solution. In addition, for application of LTH, we need to understand the structure of complexified configuration space such as critical point and gradient-flow defined by Morse function. We firstly consider the complexified configuration space, and then show our numerical results.