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Derived categories of small toric Calabi-Yau 3-folds and counting invariants

Kentaro Nagao

TL;DR

This work establishes a concrete bridge between small crepant resolutions of affine toric Calabi–Yau $3$-folds and quivers with superpotential via a explicit derived equivalence mediated by a tilting bundle. It then develops a comprehensive counting framework for perverse coherent systems, proving a wall-crossing formula for generating functions that interrelates $DT$, $PT$, and noncommutative $DT$ invariants, including explicit product expansions and $BPS$-state data. Mutations of the quiver and corresponding stability conditions are shown to preserve the moduli-space descriptions, with the tilting generator remaining a vector bundle and fixed-point data governed by torus-crystal combinatorics. The results provide structural insights into the DT/PT/NCDT landscape in the toric CY setting, enabling explicit computations and revealing deep links between geometry, representation theory, and wall-crossing phenomena.

Abstract

We first construct a derived equivalence between a small crepant resolution of an affine toric Calabi-Yau 3-fold and a certain quiver with a superpotential. Under this derived equivalence we establish a wall-crossing formula for the generating function of the counting invariants of perverse coherent systems. As an application we provide certain equations on Donaldson-Thomas, Pandeharipande-Thomas and Szendroi's invariants. Finally, we show that moduli spaces associated with a quiver given by successive mutations are realized as the moduli spaces associated the original quiver by changing the stability conditions.

Derived categories of small toric Calabi-Yau 3-folds and counting invariants

TL;DR

This work establishes a concrete bridge between small crepant resolutions of affine toric Calabi–Yau -folds and quivers with superpotential via a explicit derived equivalence mediated by a tilting bundle. It then develops a comprehensive counting framework for perverse coherent systems, proving a wall-crossing formula for generating functions that interrelates , , and noncommutative invariants, including explicit product expansions and -state data. Mutations of the quiver and corresponding stability conditions are shown to preserve the moduli-space descriptions, with the tilting generator remaining a vector bundle and fixed-point data governed by torus-crystal combinatorics. The results provide structural insights into the DT/PT/NCDT landscape in the toric CY setting, enabling explicit computations and revealing deep links between geometry, representation theory, and wall-crossing phenomena.

Abstract

We first construct a derived equivalence between a small crepant resolution of an affine toric Calabi-Yau 3-fold and a certain quiver with a superpotential. Under this derived equivalence we establish a wall-crossing formula for the generating function of the counting invariants of perverse coherent systems. As an application we provide certain equations on Donaldson-Thomas, Pandeharipande-Thomas and Szendroi's invariants. Finally, we show that moduli spaces associated with a quiver given by successive mutations are realized as the moduli spaces associated the original quiver by changing the stability conditions.

Paper Structure

This paper contains 21 sections, 59 theorems, 222 equations, 11 figures.

Key Result

Lemma 1.3

Figures (11)

  • Figure 1: $\Gamma_\sigma$
  • Figure 2: S
  • Figure 3: H
  • Figure 4: $P_\sigma$ in case Example \ref{['example']}
  • Figure 5: Universal representations on ${\mathfrak{M}}^{\sigma}_{\theta_0}(\delta)$ in case Example \ref{['example']}
  • ...and 6 more figures

Theorems & Definitions (119)

  • Definition 1.1
  • Example 1.2
  • Lemma 1.3
  • proof
  • Example 1.4
  • Lemma 1.5
  • proof
  • Proposition 1.6
  • proof
  • Proposition 1.7
  • ...and 109 more