The orbifold DT/PT vertex correspondence
Yijie Lin
TL;DR
The work develops an orbifold topological vertex framework for PT and DT theories on toric Calabi–Yau 3-orbifolds with transverse $A_{n-1}$ singularities, culminating in a full 3-leg DT/PT vertex correspondence. It constructs both DT and PT dimer/double-dimer models on orbifold graphs, derives three graphical condensation recurrences on each side, and computes explicit weight factors and sign rulings that certify the correspondence. A key outcome is an explicit formula for the PT $Z_n$-vertex in terms of loop Schur data and the establishment of multi-regular DT/PT equivalence in this orbifold setting. The approach unifies combinatorial, geometric, and representation-theoretic ingredients, enabling explicit computations of orbifold DT/PT invariants and vertex functions. The results bear on broader GW/DT/PT correspondences and crepant-resolutions-type phenomena in orbifold Calabi–Yau geometries.
Abstract
We present an orbifold topological vertex formalism for PT invariants of toric Calabi-Yau 3-orbifolds with transverse $A_{n-1}$ singularities. We give a proof of the orbifold DT/PT Calabi-Yau topological vertex correspondence. As an application, we derive an explicit formula for the PT $\mathbb{Z}_{n}$-vertex in terms of loop Schur functions and prove the multi-regular orbifold DT/PT correspondence.
