Hawk Supercomputer Helps Physicists Address the Sign Problem

Trace anomaly for different lattices and example of continuum limit
Figure 1: Right: Trace anomaly for our different lattices, and the resulting continuum extrapolation. Left: Example of continuum limit for the pressure at T = 185 MeV, with two scale settings, and both with and without tree-level correction. The bands show linear fits, and the blue error bar at 0 shows our result from Ref. [3].

With the help of world-class supercomputing resources from the Gauss Centre for Supercomputing (GCS), a team of researchers led by Prof. Zoltan Fodor at the University of Wuppertal has continued to advance the state-of-the-art in elementary particle physics. Recently, the team has turned its research efforts toward addressing the so-called sign problem. While physicists generally understand how to calculate the temperature conditions necessary for materials to transition between states of liquids, gases, plasmas, and solids, they often must dig deeper to do so under a wide variety of pressure and density conditions. While certain density conditions lend themselves to straightforward calculation or are easily observable in experiments, others are much more complex, with the most complex essentially becoming a drawn-out probability game similar to flipping a coin millions of times in order to find its slight bias. With access to the Hawk supercomputer at the High-Performance Computing Center Stuttgart, the team was able to refine its computational algorithm to more accurately address the sign problem. It published its paper in 'Physical Review Letters'.

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Principal Investigator

Prof. Zoltan Fodor

University of Wuppertal, Wuppertal