On the (in)consistency of perturbation theory at finite temperature

Fuente: arXiv
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Autori principali: Lowdon, Peter, Philipsen, Owe
Natura: Preprint
Pubblicazione: 2024
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author Lowdon, Peter
Philipsen, Owe
author_facet Lowdon, Peter
Philipsen, Owe
contents A well-known difficulty of perturbative approaches to quantum field theory at finite temperature is the necessity to address theoretical constraints that are not present in the vacuum theory. In this work, we use lattice simulations of scalar correlation functions in massive $ϕ^{4}$ theory to analyse the extent to which these constraints affect the perturbative predictions. We find that the standard perturbative predictions deteriorate even in the absence of infrared divergences at relatively low temperatures, and that this is directly connected to the analytic structure of the propagators used in the expansion. This suggests that the incorporation of non-perturbative thermal effects in the propagators is essential for a consistent perturbative formulation of scalar quantum field theories at finite temperature. By utilising the spectral constraints imposed on finite-temperature correlation functions, we explore how these effects manifest themselves in the lattice data, and discuss why the presence of distinct thermoparticle excitations provides a potential resolution to these issues.
format Preprint
id arxiv_https___arxiv_org_abs_2405_02009
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the (in)consistency of perturbation theory at finite temperature
Lowdon, Peter
Philipsen, Owe
High Energy Physics - Phenomenology
High Energy Physics - Lattice
High Energy Physics - Theory
Nuclear Theory
A well-known difficulty of perturbative approaches to quantum field theory at finite temperature is the necessity to address theoretical constraints that are not present in the vacuum theory. In this work, we use lattice simulations of scalar correlation functions in massive $ϕ^{4}$ theory to analyse the extent to which these constraints affect the perturbative predictions. We find that the standard perturbative predictions deteriorate even in the absence of infrared divergences at relatively low temperatures, and that this is directly connected to the analytic structure of the propagators used in the expansion. This suggests that the incorporation of non-perturbative thermal effects in the propagators is essential for a consistent perturbative formulation of scalar quantum field theories at finite temperature. By utilising the spectral constraints imposed on finite-temperature correlation functions, we explore how these effects manifest themselves in the lattice data, and discuss why the presence of distinct thermoparticle excitations provides a potential resolution to these issues.
title On the (in)consistency of perturbation theory at finite temperature
topic High Energy Physics - Phenomenology
High Energy Physics - Lattice
High Energy Physics - Theory
Nuclear Theory
url https://arxiv.org/abs/2405.02009