A beginner's guide to functional methods in particle physics
High Energy Physics - Phenomenology
2025-10-23 v1
Abstract
Functional methods like Dyson-Schwinger equations, the nPI effective action formalism, bound state equations and the functional renormalization group are versatile tools to study quantum field theories. They are exact, nonperturbative equations but have to be truncated for practical calculations. After a general introduction, I focus on their use in particle physics and discuss common truncations and solution techniques. The complete process from choosing a truncation to calculating observable quantities is exemplified by means of the glueball spectrum.
Cite
@article{arxiv.2510.18960,
title = {A beginner's guide to functional methods in particle physics},
author = {Markus Q. Huber},
journal= {arXiv preprint arXiv:2510.18960},
year = {2025}
}
Comments
26 pages, 16 figures, commissioned article for the Encyclopedia of Particle Physics