On the question of universality in $\RPn$ and $\On$ Lattice Sigma Models

TL;DR

This paper argues that mixed $ ext{RP}^n$ and $ ext{O}(n)$ lattice sigma models in 2D do not violate universality in their continuum limit, countering previous claims suggesting otherwise.

Contribution

It provides a theoretical analysis showing the absence of universality violation in these models, challenging earlier conflicting assertions.

Findings

No essential violation of universality in the continuum limit.

Mixed $ ext{RP}^n$ and $ ext{O}(n)$ models behave consistently with universality.

Counterarguments to previous claims are supported by the analysis.

Abstract

We argue that there is no essential violation of universality in the continuum limit of mixed $\RPn$ and $\On$ lattice sigma models in 2 dimensions, contrary to opposite claims in the literature.