4 papers · 1 filter
Wall-crossing for equivariant DT4 invariants
Arkadij Bojko, Nikolas Kuhn, Henry Liu +1
We prove the wall-crossing formula conjectured by Gross--Joyce--Tanaka for equivariant enumerative invariants of CY4 categories equipped with framing functors. We also establish a…
Wall-crossing for invariants of equivariant 3CY categories
Nikolas Kuhn, Henry Liu, Felix Thimm
We provide a wall-crossing framework for operational enumerative invariants of equivariant 3-Calabi--Yau categories arising from virtual cycles. The strategy follows ideas of Joyce…
The Blowup Formula for the Instanton Part of Vafa-Witten Invariants on Projective Surfaces
Nikolas Kuhn, Oliver Leigh, Yuuji Tanaka
We prove a blow-up formula for the generating series of virtual -genera for moduli spaces of sheaves on projective surfaces, which is related to a conjectured formula for top…
Spin structures on perfect complexes
Nikolas Kuhn
We define spin structures on perfect complexes outside of characteristic two, generalizing the usual notion for vector bundles. We give an explicit local characterization of spin s…