Workshop on the sign problem in QCD and beyond

Session

Monday afternoon

20 Jan 2025, 13:45

Lecture Hall 099 (ExWi Building) (University of Bern)

29. Easing the sign problem in many-body physics

Mr Jens Eisert

20/01/2025, 13:45

talk

The sign problem is a well-known challenge in quantum many-body physics. It presents significant obstacles for Monte Carlo sampling methods, which are otherwise powerful tools in the field. Specifically, when a system exhibits a sign problem, these methods struggle to perform efficiently. However, it is important to note that the sign problem is basis-dependent. In this talk, we will explore...

7. Lattice QCD sign problem as an inverse problem

Francesco Di Renzo

20/01/2025, 14:30

talk

Simulation of finite density lattice QCD at imaginary chemical potential is a popular workaround for the sign problem. One is then left with the problem of performing the analytic continuation of results to the real axis. We show how this continuation can be mapped to an inverse problem via the (integral) Cauchy formula.

32. Minimal pole representation and controlled analytic continuation of Matsubara response functions

Emanuel Gull

20/01/2025, 16:00

talk

Analytic continuation is a central step in the simulation of finite-temperature field theories in which numerically obtained Matsubara data are continued to the real frequency axis for a physical interpretation. Numerical analytic continuation is considered to be an ill-posed problem where uncertainties on the Matsubara axis are amplified exponentially. Here, we present a systematic and...

15. QCD deconfinement transition line up to $\mu_B=400$~MeV from finite volume lattice simulations

Ludovica Pirelli (Bergische Universität Wuppertal)

20/01/2025, 16:45

talk

The QCD cross-over line in the temperature ($T$) -- baryo-chemical potential ($\mu_B$) plane has been computed by several lattice groups by calculating the chiral order parameter and its susceptibility at finite values of $\mu_B$. In this work we focus on the deconfinement aspect of the transition between hadronic and Quark Gluon Plasma (QGP) phases. We define the deconfinement temperature as...