The linear spaces that are fixed by a given nilpotent
matrix form a subvariety of the Grassmannian. We classify these varieties for small
.
Muthiah, Weekes and Yacobi conjectured that their radical ideals are generated by
certain linear forms known as shuffle equations. We prove this conjecture for
, and we
disprove it for
.
The question remains open for nilpotent matrices arising from the affine
Grassmannian.