## Subspace varieties and signal processing, after DeLauthauwer

Ming Yang, Texas A&M

This poster explores the defectivity of secant varieties and joins
of subspace varieties. We compute the defect of many 2-secant
varieties of subspace varieties and completely determine the
defectivity and weakly-defectivity of
$\sigma_{R}(Sub_{1,L,L}\mathbb{C}^{I}\otimes \mathbb{C}^{J}\otimes
\mathbb{C}^{K})$. We also study joins of subspace varieties, when
the multilineal rank is very low. These determine uniqueness or partial
uniqueness up to finite ways of presentations.