17–21 Aug 2026
University of Helsinki Main Building
Europe/Helsinki timezone

Equation of state of hot and dense QCD using the complex Langevin equation

18 Aug 2026, 12:00
15m
F4050 (4th floor) (University of Helsinki Main Building)

F4050 (4th floor)

University of Helsinki Main Building

University of Helsinki Fabianinkatu 33 Finland
talk (15min) QCD in extreme conditions and dense nuclear matter QCD in Extreme Conditions Contributions 2

Speaker

Michael Mandl (University of Graz)

Description

A proper understanding of QCD under extreme conditions such as high temperature and densities is of fundamental importance for the theoretical description of, e.g., heavy-ion collisions, neutron stars, and the early universe. However, the non-perturbative study of QCD at non-zero baryon density from the point of view of lattice field theory is hampered by the infamous sign problem, preventing the straightforward application of established importance-sampling techniques. A possible way out is provided by the complex Langevin approach, which is based on the stochastic evolution of complexified degrees of freedom in an auxiliary time dimension. We present continuum-extrapolated results of the first complex Langevin simulations of QCD with physical pion masses, reaching high baryon densities but restricting to temperatures above the crossover. In particular, we have computed the QCD equation of state including the pressure, energy density, and various derived quantities. Moreover, we report on our recent efforts to better understand the problem of wrong convergence that complex Langevin simulations sometimes face and how existing correctness criteria compare against one another.

Authors

Daniel Unterhuber (University of Graz) Dénes Sexty (University of Graz) Michael Mandl (University of Graz)

Presentation materials

There are no materials yet.