Complex Quantum Chern-Simons

TL;DR

This paper develops a framework for constructing topological quantum field theories from Pontryagin self-dual locally compact abelian groups, connecting them to quantum Chern-Simons theory with complex gauge groups.

Contribution

It introduces a general method to build TQFTs from self-dual LCA groups and relates them to quantum Chern-Simons theory via geometric quantization.

Findings

Constructed a TQFT from any Pontryagin self-dual LCA group.

Established an alternative formulation using line bundles over quotient groups.

Applied the framework to real and finite cyclic groups, recovering quantum Chern-Simons theory.

Abstract

We lay down a general framework for how to construct a Topological Quantum Field Theory $Z_A$ defined on shaped triangulations of orientable 3-manifolds from any Pontryagin self-dual locally compact abelian group $A$. The partition function for a triangulated manifold is given by a state integral over the LCA $A$ of a certain combinations of functions which satisfy Faddeev's operator five term relation. In the cases where all elements of the LCA $A$ are divisible by 2 and it has a subgroup $B$ whose Pontryagin dual is isomorphic to $A/B$, this TQFT has an alternative formulation in terms of the space of sections of a line bundle over $(A/B)^{2}$. We apply this to the LCA $\mathbb{R}\times \mathbb{Z}/N\mathbb{Z}$ and obtain a TQFT, which we show is Quantum Chern-Simons theory at level $N$ for the complex gauge group $SL(2,\mathbb{C})$ by the use of geometric quantization.