Spectrum in the broken phase of a $\lambda\phi^4$ theory

TL;DR

This paper derives the particle spectrum in the broken phase of a $ ext{phi}^4$ theory as the coupling becomes very large, confirming recent lattice results and revealing a spectrum proportional to even integers of a renormalized mass.

Contribution

It provides an analytical derivation of the spectrum in the strong coupling limit of a $ ext{phi}^4$ theory, aligning with numerical lattice findings.

Findings

Spectrum scales as even integers of a renormalized mass.

Analytical results agree with recent lattice computations.

Spectrum behavior in the strong coupling limit is characterized.

Abstract

We derive the spectrum in the broken phase of a $\lambda\phi^4$ theory, in the limit $\lambda\to\infty$, showing that this goes as even integers of a renormalized mass in agreement with recent lattice computations.