Computing $A$-resultants via direct images

Abstract

We improve a previously known theoretic method to compute A-resultants for suitable monomial support sets due to Weyman to the extent that it becomes computationally feasible and effective. This is achieved by introducing a new algorithm for the computation of direct images of complexes of coherent sheaves on toric varieties. The procedure does not rely on Gröbner basis computations at any stage.

23 pages, 1 figure; we expect the accompanying implementation to soon be available in the computer algebra system OSCAR (www.oscar-system.org)