Workshop on the sign problem in QCD and beyond

Session

Tuesday afternoon

21 Jan 2025, 13:30

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

19. Prospects for Quantum Simulations of the Strong Coupling Expansion

Wolfgang Unger

21/01/2025, 13:30

talk

We present Monte Carlo simulations for the phase diagram based on the strong coupling expansion including $\mathcal{O}(\beta^2)$ and discuss the severity of the sign problem as a function of the inverse gauge coupling $\beta$, which limits the range of validity of the strong coupling expansion. We also present the formulation of the strong coupling expansion that is suitable for quantum...

18. Correlated Cluster Algorithms

Thea Budde (ETH Zürich)

21/01/2025, 14:15

talk

Cluster algorithms are Monte Carlo algorithms that provide efficient non-local updates of the configurations. They can avoid critical slowing down when approaching a second-order phase transition and solve severe sign problems in well-tailored cases. The clusters group degrees of freedom that can be updated independently of one another. While highly efficient, the range of models that can be...

17. Abelian Gauge Theories in 1+1D with Correlated Cluster Algorithms

Joao C. Pinto Barros (Institute for Theoretical Physics, ETH Zurich)

21/01/2025, 15:00

talk

The Hamiltonian formulation of lattice gauge theories offers a pathway to new quantum and classical simulation techniques, providing new ways to circumvent different sign problems.In this work, we address different formulations of various Abelian gauge theories within the Hamiltonian framework in 1+1 dimensions. Using Correlated Cluster Algorithms, we exactly solve Gauss’s law for...

23. Wormhole quantum Monte Carlo for quantum dissipative spin systems

Manuel Weber (TUDresden)

21/01/2025, 16:15

talk

The phases and phase transitions of low-dimensional quantum magnets are often described using simple quantum spin models. It is an open question how the properties of these systems are affected by a coupling to the environment, which is always present in any experimental realization. One of the simplest setups for such an open quantum system is the spin-boson model where a single spin is...

3. Rotating gluodynamics and QCD: sign problem, mixed inhomogeneous phase and moment of inertia

Artem Roenko (JINR)

21/01/2025, 17:00

talk

This report is devoted to the lattice study of rotating gluodynamics and QCD properties. The lattice simulation is conducted in a co-rotating reference frame, where the rotation is reduced to the effects of curved space-time. Unfortunately, a direct simulation of this system is hampered by the sign problem, which arises both in gluonic and fermionic sectors. To overcome the sign problem, we...