An introduction to effective potential methods in field theory

TL;DR

This paper provides a comprehensive pedagogical overview of effective potential methods in field theory, covering theoretical foundations, computational techniques, and applications in cosmology and particle physics.

Contribution

It offers a detailed review of effective potential calculation methods, including radiative and thermal corrections, and explores their applications in symmetry breaking, vacuum stability, and early universe phenomena.

Findings

Radiative corrections can induce spontaneous symmetry breaking.

The electroweak vacuum may be metastable due to quantum effects.

Effective potential methods are crucial for understanding cosmological phase transitions.

Abstract

In this chapter we give a pedagogical introduction to effective potential methods in field theories. We first review the general functional methods leading to the concept of effective action and effective potential. Focusing on the effective potential we review the methods to compute radiative contributions, starting from the original 1973 seminal paper by Sidney Coleman and Erick Weinberg on one-loop corrections, along with its improvement by the renormalization group equations, as well as some basic results from thermal field theory, including the one-loop thermal corrections to the effective potential. We concentrate on some physical applications of the effective potential: i) the possibility of spontaneous symmetry breaking by radiative corrections, ii) the metastability of the electroweak vacuum in the Standard Model, and iii) the relevance of quantum effects in the dynamics of Higgs inflation. We then apply the previous results to cosmological phase transitions in the early universe and the possibility of generating a stochastic background of gravitational waves as well as primordial black holes.