The indeterminacy locus of the Voisin map
Giosuè Emanuele Muratore
Abstract
Beauville and Donagi proved that the variety of lines $F(Y)$ of a smooth cubic fourfold $Y$ is a hyperkähler variety. Recently, C. Lehn, M.Lehn, Sorger and van Straten proved that one can naturally associate a hyperKähler variety $Z(Y)$ to the variety of twisted cubics on $Y$. Then, Voisin defined a degree 6 rational map $ψ:F(Y)\times F(Y)\dashrightarrow Z(Y)$. We will show that the indeterminacy locus of $ψ$ is the locus of intersecting lines.
