# Describing phase transitions in field theory by self-similar approximants

## TL;DR

This paper demonstrates that self-similar approximation theory effectively describes phase transitions in quantum field theory by extrapolating asymptotic series, with applications to critical temperature, exponents, and deconfinement temperature.

## Contribution

It introduces self-similar approximants as a novel method for analyzing phase transitions in quantum field theory, providing results consistent with numerical data.

## Key findings

- Accurately predicts critical temperature variations.
- Calculates critical exponents matching numerical results.
- Estimates deconfinement temperature in QCD.

## Abstract

Self-similar approximation theory is shown to be a powerful tool for describing phase transitions in quantum field theory. Self-similar approximants present the extrapolation of asymptotic series in powers of small variables to the arbitrary values of the latter, including the variables tending to infinity. The approach is illustrated by considering three problems: (i) The influence of the coupling parameter strength on the critical temperature of the O(N)-symmetric multicomponent field theory. (ii) The calculation of critical exponents for the phase transition in the O(N)-symmetric field theory. (iii) The evaluation of deconfinement temperature in quantum chromodynamics. The results are in good agreement with the available numerical calculations, such as Monte Carlo simulations, Pade-Borel summation, and lattice data.