Syzygies and singularities of tensor product surfaces of bidegree (2,1)

Hal Schenck, Alexandra Seceleanu, Javid Validashti

Let U be a basepoint free four-dimensional subspace of the space of sections of O(2,1) on P^1 x P^1. The sections corresponding to U determine a regular map p_U: P^1 x P^1 --> P^3.…