Lefschetz thimble method applied to 1 dim Thirring model at finite density

by Fujii Hirotsugu (The University of Tokyo)

Monday 30 Nov 2015, 13:30 → 14:30 Asia/Tokyo

433, Main Research Building (RIKEN Wako)

Date: Nov 30 (Mon) Time: 13:30 - Place: Main Research bldg. 433 Speaker: Hirotsugu Fujii (The University of Tokyo) Title: Lefschetz thimble method applied to 1 dim Thirring model at finite density Abstract: The Thirring model at finite chemical potential in (0+1) dimensions suffers from the sign problem due to the fermion determinant in the path integration. Complexifying the field variables, we analyze the thimble structure of the lattice model from the viewpoint of the determinant zeros, the critical points of the gradient flow, and the Stokes jump. We show that multi thimbles constribute to the partition function in the crossover region from the low to high density phases, and demonstrate this fact with a reduced model with one variable. We also perform a numerical simulation on the single dominant thimble and find that the results are in agreement with the expectation of the analytic study. See more QHP seminars