Axel Hultman

activity

20042021

most citedThe topology of the space of matrices of Barvinok rank two

3 citations · 10 across the 17 of their papers we have counts for

collaborators

19 papers

math.CO2021

Boolean complexes of involutions

Axel Hultman, Vincent Umutabazi

Let (W,S) be a Coxeter system. We introduce the boolean complex of involutions of W which is an analogue of the boolean complex of W studied by Ragnarsson and Tenner. By applying d…

math.CO2019

Smoothness of Schubert varieties indexed by involutions in finite simply laced types

Axel Hultman, Vincent Umutabazi

We prove that in finite, simply laced types, every Schubert variety indexed by an involution which is not the longest element of some parabolic subgroup is singular.

math.CO2017

Topology of posets with special partial matchings

Nancy Abdallah, Mikael Hansson, Axel Hultman

Special partial matchings (SPMs) are a generalisation of Brenti's special matchings. Let a \emph{pircon} be a poset in which every non-trivial principal order ideal is finite and a…

math.CO2017

A word property for twisted involutions in Coxeter groups

Mikael Hansson, Axel Hultman

Given an involutive automorphism $θ$ of a Coxeter system $(W, S)$ , let $I (θ) \subseteq W$ denote the set of twisted involutions. We provide a minimal set of moves that ca…

math.CO2016

Combinatorial Invariance of Kazhdan-Lusztig-Vogan Polyomials for Fixed Point Free Involutions

Nancy Abdallah, Axel Hultman

When $S p (2 n, C)$ acts on the flag variety of $S L (2 n, C)$ , the orbits are in bijection with fixed point free involutions in the symmetric group $S_{2 n}$ . In this cas…

math.CO2014★ 2 cited

Supersolvability and the Koszul property of root ideal arrangements

Axel Hultman

A root ideal arrangement $A_{I}$ is the set of reflecting hyperplanes corresponding to the roots in an order ideal $I$ of the root poset on the positive roots of a finite crystallogr…