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arXiv · 1606.02742

A study of symmetry breaking in a relativistic Bose gas using the contraction algorithm

Andrei Alexandru·Gokce Basar·Paulo Bedaque·Gregory W. Ridgway·Neill C. Warrington
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Abstract

A relativistic Bose gas at finite density suffers from a sign problem that makes direct numerical simulations not feasible. One possible solution to the sign problem is to re-express the path integral in terms of Lefschetz thimbles. Using this approach we study the relativistic Bose gas both in the symmetric phase (low-density) and the spontaneously broken phase (high-density). In the high-density phase we break explicitly the symmetry and determine the dependence of the order parameter on the breaking. We study the relative contributions of the dominant and sub-dominant thimbles in this phase. We find that the sub-dominant thimble only contributes substantially when the explicit symmetry breaking is small, a regime that is dominated by finite volume effects. In the regime relevant for the thermodynamic limit, this contribution is negligible.

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Andrei Alexandru, Gokce Basar, Paulo Bedaque, Gregory W. Ridgway, Neill C. Warrington. 2016-06-08. A study of symmetry breaking in a relativistic Bose gas using the contraction algorithm. https://doi.org/10.1103/physrevd.94.045017

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