Quantum periods of Calabi-Yau fourfolds

TL;DR

This paper investigates quantum periods and Picard-Fuchs equations of Calabi-Yau fourfolds, revealing unique monodromy properties, constructing integral quantum periods, and computing Gromov-Witten and BPS invariants to deepen understanding of their quantum geometry.

Contribution

It introduces the study of quantum periods of Calabi-Yau fourfolds with non-maximally unipotent monodromy and constructs explicit integral quantum periods for these cases.

Findings

Large volume points are regular singular points with non-maximal unipotent monodromy.

Constructed integral quantum periods and analyzed their properties.

Computed genus zero Gromov-Witten, meeting, and genus one BPS invariants.

Abstract

In this work we study the quantum periods together with their Picard-Fuchs differential equations of Calabi-Yau fourfolds. In contrast to Calabi-Yau threefolds, we argue that the large volume points of Calabi-Yau fourfolds generically are regular singular points of the Picard-Fuchs operators of non-maximally unipotent monodromy. We demonstrate this property in explicit examples of Calabi-Yau fourfolds with a single Kahler modulus. For these examples we construct integral quantum periods and study their global properties in the quantum Kahler moduli space with the help of numerical analytic continuation techniques. Furthermore, we determine their genus zero Gromov-Witten invariants, their Klemm-Pandharipande meeting invariants, and their genus one BPS invariants. In our computations we emphasize the features attributed to the non-maximally unipotent monodromy property. For instance, it implies the existence of integral quantum periods that at large volume are purely worldsheet instanton generated. To verify our results, we also present intersection theory techniques to enumerate lines with a marked point on complete intersection Calabi-Yau fourfolds in Grassmannian varieties.