A categorical 𝔰𝔩₂ action on some moduli spaces of sheaves

Abstract

We study certain sequences of moduli spaces of sheaves on K3 surfaces, building on work of Markman [J. Algebraic Geom. 10 (2001), pp. 623–694], Yoshioka [J. Reine Angew.Math. 515 (1999), pp. 97–123], and Nakajima [Convolution on homology groups of moduli spaces of sheaves on K3 surfaces, Contemp. Math., vol. 322, Amer. Math. Soc., Providence, RI, 2003, pp. 75–87]. We show that these sequences can be given the structure of a geometric categorical s l 2 \mathfrak {sl}_2 action in the sense of Cautis, Kamnitzer, and Licata. As a corollary, we get an equivalence between derived categories of some moduli spaces that are birational via stratified Mukai flops.