English

Semistable refined Vafa-Witten invariants

Algebraic Geometry 2025-12-30 v3

Abstract

For any smooth complex projective surface SS, we construct semistable refined Vafa-Witten invariants of SS which prove the main conjecture of arXiv:1810.00078. This is done by extending part of Joyce's universal wall-crossing formalism to equivariant K-theory, and to moduli stacks with symmetric obstruction theories, particularly moduli stacks of sheaves on Calabi-Yau threefolds. An important technical tool which we introduce is the symmetrized pullback, along smooth morphisms, of symmetric obstruction theories.

Keywords

Cite

@article{arxiv.2309.03673,
  title  = {Semistable refined Vafa-Witten invariants},
  author = {Henry Liu},
  journal= {arXiv preprint arXiv:2309.03673},
  year   = {2025}
}

Comments

33 pages. v3: the nonzero H1 case of the main theorem has been weakened due to a mistake in previous versions, plus minor revisions based on referee comments. Journal version

R2 v1 2026-06-28T12:15:15.284Z