a1 Department of Mathematics National University of Ireland Galway Ireland e-mail: firstname.lastname@example.org
a2 School of Mathematics University of Birmingham Birmingham B15 2TT United Kingdom e-mail: email@example.com
The conjugacy classes of so-called special involutions parameterize the constituents of the action of a finite Coxeter group on the cohomology of the complement of its complexified hyperplane arrangement. In this note we give a short intrinsic characterisation of special involutions in terms of so-called bulky parabolic subgroups.
(Received May 20 2004)
(Revised September 20 2004)
2000 Mathematics subject classification