On the Hilbert scheme of degeneracy loci of twisted differential forms
arXiv:1401.8188 · doi:10.1090/tran/6637
Abstract
We prove that, for 3 < m < n-1, the Grassmannian of m-dimensional subspaces of the space of skew-symmetric forms over a vector space of dimension n is birational to the Hilbert scheme of the degeneracy loci of m global sections of Omega(2), the twisted cotangent bundle on P^{n-1}. For 3=m<n-1 and n odd, this Grassmannian is proved to be birational to the set of Veronese surfaces parametrized by the Pfaffians of linear skew-symmetric matrices of order n.
arXiv comment19 pages. Minor corrections, exposition improved. To appear in Trans. Amer. Math. Soc