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arXiv · 1711.07898

Benchmark results in the 2D lattice Thirring model with a chemical potential

Venkitesh Ayyar·Shailesh Chandrasekharan·Jarno Rantaharju
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Abstract

We study the two dimensional lattice Thirring model in the presence of a fermion chemical po- tential. Our model is asymptotically free, contains massive fermions that mimic a baryon and light bosons that mimic pions. Hence it is a useful toy model for QCD, especially since it too suffers from a sign problem in the auxiliary field formulation in the presence of a fermion chemical potential. In this work we formulate the model in both the world line and fermion-bag representations and show that the sign problem can be completely eliminated with open boundary conditions when the fermions are massless. Hence we are able accurately compute a variety of interesting quantities in the model, and these results could provide benchmarks for other methods that are being developed to solve the sign problem in QCD.

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Venkitesh Ayyar, Shailesh Chandrasekharan, Jarno Rantaharju. 2017-11-21. Benchmark results in the 2D lattice Thirring model with a chemical potential. https://doi.org/10.1103/physrevd.97.054501

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