Workshop on the sign problem in QCD and beyond

Session

Thursday afternoon

23 Jan 2025, 14:00

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

6. Constant path integral contour shifts

Johann Ostmeyer (University of Bonn)

23/01/2025, 14:00

talk

The Fermi-Hubbard model suffers from a severe sign problem, both for non-zero chemical potentials and on non-bipartite lattices. Over the years, considerable progress has been made in alleviating the sign problem by deforming the integration contour of the path integral into the complex plane. In this talk, I am going to present a surprisingly simple and yet powerful contour deformation by...

37. Contour optimisation for the sign problem with an efficient evaluation of the Jacobian

Prof. Michael Kroyter (Holon Institute of Technology)

23/01/2025, 14:45

talk

In previous work, with Francis Bursa, we considered the approach of addressing the sign problem using simple contour deformations. As a toy model for examining the approach we used the one-dimensional Bose gas with chemical potential. The contour deformations that were considered are local and they lead to simple forms of the Jacobian that can be simulated fast.

However, the periodic...

34. Quantum Computing for Lattice Field Theory

Lena Funcke (University of Bonn)

23/01/2025, 16:15

talk

In this talk, we review recent advances in applying quantum computing to lattice field theory. Quantum technology offers the prospect to efficiently simulate sign-problem afflicted regimes in lattice field theory, such as the presence of topological terms, chemical potentials, and out-of-equilibrium dynamics. First proof-of-concept simulations of Abelian and non-Abelian gauge theories in...

21. Variational Quantum Eigensolver for (2+1)-Dimensional QED at Finite Density

Emil Otis Rosanowski

23/01/2025, 17:00

talk

In this talk, we present an implementation of multiple fermion flavors in both the Kogut-Susskind and Wilson formulations for quantum simulations of (2+1)-dimensional Quantum Electrodynamics (QED). Our first results show a particular type of level crossing with one flavor of fermions at zero density, as expected from analytical Chern number calculations. Moving forward, we explore the...