2017/03/14 by Nicolas Garrón, Nicolas Garron, Kurt Langfeld · 21 citations
Mathematics · Physics and Astronomy · #Fermion #Gaussian #High-Energy Particle Collisions Research #Mathematical analysis #Mathematical physics #Mathematics #Particle physics theoretical and experimental studies #Partition function (quantum field theory) #Physics #Quantum #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum field theory #Quantum mechanics #Quark #Sign (mathematics) #Statistical physics #hep-lat #hep-ph #hep-th
paper · pdf · doi:10.1140/epjc/s10052-017-5039-7
published in The European Physical Journal C 77(7) (Springer Science+Business Media) · 13 pages, 10 figures
arxiv created 2017/03/14 · openalex publication_date 2017/07/01 · arxiv updated 2017/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 analog. 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.