Moduli spaces of framed symplectic and orthogonal bundles on P2 and the K-theoretic Nekrasov partition functions (vol 106, 2016)

We give a scheme-theoretic description of mu(-1)(0) and mu(-1)(0)//Sp(2), where mu, is the moment map defining the space of ADHM data associated to framed SO(3, R)-instantons with instanton number 1. The irreducible component in mu(-1)(0)//Sp(2), other than the Zariski closure of the instanton moduli space, is non-reduced, which is a corrigendum to [Choy (2016), Theorem 4.3]. We further describe this component using the factorization property Braverman et al. (2006). (C) 2016 Elsevier B.V. All rights reserved.