Dual Pairs of Gauged Linear Sigma Models and Derived Equivalences of Calabi-Yau threefolds

TL;DR

This paper explores dualities among skew symplectic sigma models, revealing derived equivalences of Calabi-Yau threefolds through phase structure analysis, partition function calculations, and algebraic geometry insights.

Contribution

It introduces a duality framework connecting non-birational Calabi-Yau threefolds via skew symplectic sigma models and develops new techniques for computing two-sphere partition functions.

Findings

Identified dualities linking non-birational Calabi-Yau threefolds.

Confirmed derived equivalences through partition function comparisons.

Developed systematic methods for Mellin-Barnes integral evaluations.

Abstract

In this work we study the phase structure of skew symplectic sigma models, which are a certain class of two-dimensional N = (2,2) non-Abelian gauged linear sigma models. At low energies some of them flow to non-linear sigma models with Calabi-Yau target spaces, which emerge from non-Abelian strong coupling dynamics. The observed phase structure results in a non-trivial duality proposal among skew symplectic sigma models and connects non-complete intersection Calabi-Yau threefolds, that are non-birational among another, in a common quantum Kahler moduli space. As a consequence we find non-trivial identifications of spectra of topological B-branes, which from a modern algebraic geometry perspective imply derived equivalences among Calabi-Yau varieties. To further support our proposals, we calculate the two sphere partition function of skew symplectic sigma models to determine geometric invariants, which confirm the anticipated Calabi-Yau threefold phases. We show that the two sphere partition functions of a pair of dual skew symplectic sigma models agree in a non-trivial fashion. To carry out these calculations, we develop a systematic approach to study higher-dimensional Mellin-Barnes type integrals. In particular, these techniques admit the evaluation of two sphere partition functions for gauged linear sigma models with higher rank gauge groups, but are applicable in other contexts as well.