16 citations · 27 across the 4 of their papers we have counts for
7 papers
Exponents for B-stable ideals
Eric Sommers, Julianna Tymoczko
Let G be a simple algebraic group over the complex numbers containing a Borel subgroup B. Given a B-stable ideal I in the nilradical of the Lie algebra of B, we define natural numb…
Normality of very even nilpotent varieties in D_2l
Eric Sommers
For the classical groups, Kraft and Procesi have resolved the question of which nilpotent orbits have closures which are normal and which are not, with the exception of the very ev…
B-stable ideals in the nilradical of a Borel subalgebra
Eric Sommers
We count the number of strictly positive -stable ideals in the nilradical of a Borel subalgebra and prove that the minimal roots of any -stable ideal are conjugate by an elem…
A characterization of Dynkin elements
Paul E. Gunnells, Eric Sommers
We give a characterization of the Dynkin elements of a simple Lie algebra. Namely, we prove that one-half of a Dynkin element is the unique point of minimal length in its N-region.…
Normality of nilpotent varieties in
Eric Sommers
We determine which nilpotent orbits in have normal closure and which do not. We also verify a conjecture about small representations in rings of functions on nilpotent orbit…
Component groups of unipotent centralizers in good characteristic
George J. McNinch, Eric Sommers
Let G be a connected, reductive group over an algebraically closed field of good characteristic. For u in G unipotent, we describe the conjugacy classes in the component group A(u)…