Asymptotic expansions of the Witten-Reshetikhin-Turaev Invariants of Mapping Tori I

TL;DR

This paper studies the asymptotic behavior of Witten-Reshetikhin-Turaev invariants for mapping tori, using geometric quantization and Picard-Lefschetz theory, extending previous assumptions to include all pseudo-Anosov classes.

Contribution

It provides a full asymptotic expansion for these invariants under weaker assumptions, applying to all pseudo-Anosov mapping classes on punctured tori.

Findings

Applicable to all pseudo-Anosov classes on punctured tori

Introduces new asymptotic expansion techniques for oscillatory integrals

Extends previous assumptions on fixed point sets in TQFT analysis

Abstract

In this paper we engage in a general study of the asymptotic expansion of the Witten-Reshetikhin-Turaev invariants of mapping tori of surface mapping class group elements. We use the geometric construction of the Witten-Reshetikhin-Turaev TQFT via the geometric quantization of moduli spaces of flat connections on surfaces. We identify assumptions on the mapping class group elements that allow us to provide a full asymptotic expansion. In particular, we show that our results apply to all pseudo-Anosov mapping classes on a punctured torus and show by example that our assumptions on the mapping class group elements are strictly weaker than hitherto successfully considered assumptions in this context. The proof of our main theorem relies on our new results regarding asymptotic expansions of oscillatory integrals, which allows us to go significantly beyond the standard transversely cut out assumption on the fixed point set. This makes use of Picard-Lefschetz theory for Laplace integrals.