Linear spaces of matrices of constant rank and instanton bundles

Abstract

We present a new method to study 4-dimensional linear spaces of skew-symmetric matrices of constant co-rank 2, based on rank 2 vector bundles on P3 and derived category tools. The method allows one to prove the existence of new examples of size 10×10 and 14×14 via instanton bundles of charge 2 and 4 respectively, and it provides an explanation for what used to be the only known example (Westwick 1996 [25]). We also give an algorithm to construct explicitly a matrix of size 14 of this type.