English

A categorification of the quantum Lefschetz principle

Algebraic Geometry 2024-11-05 v2 K-Theory and Homology

Abstract

The quantum Lefschetz formula explains how virtual fundamental classes (or structure sheaves) of moduli stacks of stable maps behave when passing from an ambient target scheme to the zero locus of a section. It is only valid under special assumptions (genus 00, regularity of the section and convexity of the bundle). In this paper, we give a general statement at the geometric level removing these assumptions, using derived geometry. Through a study of the structure sheaves of derived zero loci we deduce a categorification of the formula in the \infty-categories of quasi-coherent sheaves. We also prove that Manolache's virtual pullbacks can be constructed as derived pullbacks, and use them to recover the classical Quantum Lefschetz formula when its hypotheses are satisfied.

Keywords

Cite

@article{arxiv.2002.03990,
  title  = {A categorification of the quantum Lefschetz principle},
  author = {David Kern},
  journal= {arXiv preprint arXiv:2002.03990},
  year   = {2024}
}

Comments

24 pages; comments are very much welcome. V2: Major revision; corrected several mistakes and improved exposition

R2 v1 2026-06-23T13:37:18.617Z