2 problems

General infinitesimal Terracini Lemma. $X$ is $m$-defective if and only if, given a general zero-dimensional curvilinear scheme $\gamma$ of length $m+1$ contained in $X$, the dimen…

Let $X$ be a Segre variety, and let $I(\tau(X))$ denote the homogeneous ideal of its tangential variety. The relevant Schur-module factors are expressed using exterior powers…