4 papers
Tangent spaces of spherical Schubert varieties and counterexamples to the reducedness conjecture
Marc Besson, Jiuzu Hong, Huanhuan Yu
Given a simply-connected simple algebraic group , we determine the tangent space of any Finkelberg-MirkoviÄ Schubert scheme at the base point of the affine Grassmannian of .…
Reduction rules for Demazure modules
Marc Besson, Sam Jeralds, Joshua Kiers
For a complex reductive group and a Borel subgroup, we provide a reduction rule for certain weight multiplicities in Demazure modules : given a weight $…
Smooth locus of twisted affine Schubert varieties and twisted affine Demazure modules
Marc Besson, Jiuzu Hong
Let be a special parahoric group scheme of twisted type over the ring of formal power series over , excluding the absolutely special case of $A_{2\ell}^{(…
Geometric invariant theory and stretched Kostka quasi-polynomials
Marc Besson, Sam Jeralds, Joshua Kiers
For a semisimple, simply-connected complex algebraic group and two dominant integral weights , we consider the dimensions of weight spaces of weight in…