The non-Lefschetz locus of vector bundles of rank 2 over ${\mathbb{P}}^2$

Emanuela Marangone

A finite length graded $R$-module $M$ has the Weak Lefschetz Property if there is a linear element $\ell$ in $R$ such that the multiplication map $\times \ell :M_i\to M_{i+1}$ has m…