# Galois conjugated tensor fusion categories and non-unitary CFT

## TL;DR

This paper extends the MPO formalism for string-net PEPS to include non-unitary solutions, enabling explicit lattice realizations of Galois conjugated TQFTs with preserved topological properties despite non-Hermitian Hamiltonians.

## Contribution

It introduces a generalized MPO formalism for non-unitary solutions of the pentagon equation, providing lattice models for Galois conjugated TQFTs and topological sector constructions in non-unitary contexts.

## Key findings

- Constructed topological sectors for Yang-Lee theory using strange correlators.
- Demonstrated non-unitary hard hexagon model in Yang-Lee universality class.
- Showed topological properties persist despite non-Hermitian Hamiltonians.

## Abstract

We provide a generalisation of the matrix product operator (MPO) formalism for string-net projected entangled pair states (PEPS) to include non-unitary solutions of the pentagon equation. These states provide the explicit lattice realisation of the Galois conjugated counterparts of (2+1) dimensional TQFTs, based on tensor fusion categories. Although the parent Hamiltonians of these renormalisation group fixed point states are non-Hermitian, many of the topological properties of the states still hold, as a result of the pentagon equation. We show by example that the the topological sectors of the Yang-Lee theory (the non-unitary counterpart of the Fibonacci fusion category) can be constructed even in the absence of closure under Hermitian conjugation of the basis elements of the Ocneanu tube algebra. We argue that this can be generalised to the non-unitary solutions of all $SU(2)$ level $k$ models. The topological sector construction is demonstrated by applying the concept of strange correlators to the Yang-Lee model, giving rise to a non-unitary version of the classical hard hexagon model in the Yang-Lee universality class and obtaining all generalised twisted boundary conditions on a finite cylinder of the Yang-Lee edge singularity.