Gauge origami and quiver W-algebras IV: Pandharipande--Thomas $qq$-characters
Taro Kimura, Go Noshita
TL;DR
This work develops a contour-integral framework for the K-theoretic equivariant 3-vertex in gauge origami, showing that, with an appropriate JK reference vector, both the equivariant DT3 and PT3 vertices emerge from the same integrand. It systematically analyzes DT3, PT3, and their higher-rank generalizations, establishing a DT/PT correspondence and mapping PT3 to Macdonald-refined and refined topological vertices in several limits. A central advance is the introduction of Pandharipande–Thomas $qq$-characters as operator lifts of PT3 data, with free-field realizations and screening charges tying the counting problems to quantum toroidal $rak{gl}_1$ structure. The results illuminate wall-crossing phenomena in this setting and provide a robust framework to study higher-rank and supergroup generalizations, including tetrahedron instantons. Collectively, the paper bridges gauge-theory partition functions, refined topological string vertices, and BPS/CFT operators in a unified JK-residue/dyson–Schwinger context with potential implications for enumerative geometry and quantum algebras.
Abstract
We develop a contour integral formalism for computing the K-theoretic equivariant 3-vertex. Within the Jeffrey--Kirwan (JK) residue framework, we show that, by an appropriate choice of the reference vector, both the equivariant Donaldson--Thomas (DT) and Pandharipande--Thomas (PT) 3-vertices can be extracted from the same integrand. We analyze three distinct limits of the PT 3-vertex, recovering the unrefined topological vertex, the refined topological vertex, and the Macdonald refined topological vertex. Higher-rank extensions of PT counting and the DT/PT correspondence are also explored. From a quantum algebraic perspective, we construct an operator version of the equivariant PT 3-vertex and term it the Pandharipande--Thomas $qq$-character. We then discuss its connection with the quantum toroidal $\mathfrak{gl}_{1}$.
