6 papers
Namikawa--Weyl groups of symplectic quotient singularities
Gwyn Bellamy, Gerhard Röhrle, Johannes Schmitt
We classify the Namikawa--Weyl groups associated to symplectic quotient singularities when is a symplectic reflection group. Our classification shows that every irreducib…
On Normalizers of Parabolic Subgroups of Quaternionic Reflection Groups
Gerhard Roehrle, Johannes Schmitt
By work of Howlett and Muraleedaran--Taylor, a parabolic subgroup of a real or complex reflection group always admits a complement in its normalizer. In this note, we investigate t…
Parabolic Normalizers in Finite Coxeter Groups as Subdirect Products
J. Matthew Douglass, Götz Pfeiffer, Gerhard Roehrle
We revisit the structure of the normalizer of a parabolic subgroup in a finite Coxeter group , originally described by Howlett. Building on Howlett's Lemma, which p…
On connected subgraph arrangements
Lorenzo Giordani, Tilman Möller, Paul Mücksch +1
Recently, Cuntz and Kühne introduced a particular class of hyperplane arrangements stemming from a given graph , so called connected subgraph arrangements . In this note we…
On good subgroups, Springer maps, and overgroups of distinguished unipotent elements in reductive groups
Michael Bate, Sören Böhm, Benjamin Martin +1
Suppose is a simple algebraic group defined over an algebraically closed field of good characteristic . In 2018 Korhonen showed that if is a connected reductive subgroup…
Free multiderivations of connected subgraph arrangements
Paul Mücksch, Gerhard Roehrle, Sven Wiesner
Cuntz and Kühne introduced the class of connected subgraph arrangements , depending on a graph , and classified all graphs such that the corresponding arrangement …