paper

Computing global Ext for complexes

arXiv:2509.25103 · doi:10.1016/j.jpaa.2026.108365

Abstract

We give a computational algorithm for computing Ext groups between bounded complexes of coherent sheaves on a projective variety, and we describe an implementation of this algorithm in Macaulay2. In particular, our results yield methods for computing derived global sections of bounded complexes of coherent sheaves and mutations of exceptional collections.

9 pages

Computing global Ext for complexes · wovepaper