Shifted symplectic structures on derived Quot-stacks II -- Derived Quot-schemes as dg manifolds
Dennis Borisov, Ludmil Katzarkov, Artan Sheshmani
TL;DR
The paper proves that derived Quot-stacks, built from graded submodules with a fixed Hilbert polynomial $h(\lambda)$, are representable by dg manifolds of finite type, advancing the program to study shifted symplectic structures on moduli of coherent sheaves on Calabi–Yau manifolds. It builds a tower of affine dg manifolds encoding $A_\infty$-structures and morphisms, then imposes open conditions to model submodules and develops three quotient strategies (partial, algebraic, geometric) to mod out symmetries, showing agreement with the classical derived Quot construction. The core result shows the homotopy limit in derived stacks is represented by a dg manifold of finite type, obtained by a colimit of almost-free dg algebras over $\mathbf{Gr}_{[a,b]}$ and refining with coherence of cohomology to a finite-type model. This yields a concrete dg-Quot-manifold that enables direct application of shifted-symplectic methods to derived moduli of coherent sheaves.
Abstract
It is proved that derived Quot-schemes, as defined by Ciocan-Fontanine and Kapranov, are represented by dg manifolds of finite type. This is the second part if a work aimed to analyze shifted symplectic structures on moduli spaces of coherent sheaves on Calabi--Yau manifolds. The first part related dg manifolds to derived schemes as defined by Toën and Vezzosi.
