A version of the Berglund-H\"ubsch-Henningson duality with non-abelian groups

TL;DR

This paper extends the Saito duality to non-abelian groups in the context of mirror symmetry, proving a generalized equivariant duality that holds under a specific parity condition, with implications for Calabi-Yau threefolds.

Contribution

It introduces a non-abelian generalization of Saito duality and establishes conditions under which the duality holds for invertible polynomials with non-abelian symmetry groups.

Findings

Duality holds under the parity condition (PC).

Pairs satisfying PC exhibit symmetric Hodge numbers.

Generalization applies to non-abelian symmetry groups in mirror symmetry.

Abstract

A. Takahashi suggested a conjectural method to find mirror symmetric pairs consisting of invertible polynomials and symmetry groups generated by some diagonal symmetries and some permutations of variables. Here we generalize the Saito duality between Burnside rings to a case of non-abelian groups and prove a "non-abelian" generalization of the statement about the equivariant Saito duality property for invertible polynomials. It turns out that the statement holds only under a special condition on the action of the subgroup of the permutation group called here PC ("parity condition"). An inspection of data on Calabi-Yau threefolds obtained from quotients by non-abelian groups shows that the pairs found on the basis of the method of Takahashi have symmetric pairs of Hodge numbers if and only if they satisfy PC.