Controlling the sign problem in finite-density quantum field theory

Garron, Nicolas ORCID: 0000-0002-4428-3984 and Langfeld, Kurt ORCID: 0000-0002-4368-3580 (2017) Controlling the sign problem in finite-density quantum field theory. EUROPEAN PHYSICAL JOURNAL C, 77 (7). 470-.

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Abstract

Quantum field theories at finite matter densities generically possess a partition function that is exponentially suppressed with the volume compared to that of the phase quenched analogue. The smallness arises from an almost uniform distribution for the phase of the fermion determinant. Large cancellations upon integration is the origin of a poor signal to noise ratio. We study three alternatives for this integration: the Gaussian approximation, the "telegraphic" approximation, and a novel expansion in terms of theory-dependent moments and universal coefficients. We have tested the methods for QCD at finite densities of heavy quarks. We find that for two of the approximations the results are extremely close - if not identical - to the full answer in the strong sign problem regime.

Item Type:	Article
Additional Information:	13 pages, 10 figures
Uncontrolled Keywords:	hep-lat, hep-lat, hep-ph, hep-th
Depositing User:	Symplectic Admin
Date Deposited:	10 Apr 2017 09:26
Last Modified:	15 Mar 2024 12:57
DOI:	10.1140/epjc/s10052-017-5039-7
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3006920