
arXiv: 1208.1944
The lattice of intersections of reflecting hyperplanes of a complex reflection group W W may be considered as the poset of 1 1 -eigenspaces of the elements of W W . In this paper we replace 1 1 with an arbitrary eigenvalue and study the topology and homology representation of the resulting poset. After posing the main question of whether this poset is shellable, we show that all its upper intervals are geometric lattices and then answer the question in the affirmative for the infinite family G ( m , p , n ) G(m,p,n) of complex reflection groups, and the first 31 of the 34 exceptional groups, by constructing CL-shellings. In addition, we completely determine when these eigenspaces of W W form a K ( π , 1 ) K(\pi ,1) (resp. free) arrangement. For the symmetric group, we also extend the combinatorial model available for its intersection lattice to all other eigenvalues by introducing balanced partition posets , presented as particular upper order ideals of Dowling lattices, study the representation afforded by the top (co)homology group, and give a simple map to the posets of pointed d d -divisible partitions.
Configurations and arrangements of linear subspaces, subspace arrangements, Group Theory (math.GR), Eilenberg-Mac Lane spaces, divisible partitions, Combinatorics of partially ordered sets, Group actions on combinatorial structures, Dowling lattices, Reflection and Coxeter groups (group-theoretic aspects), Combinatorial aspects of representation theory, reflection groups, ribbon representations, FOS: Mathematics, Mathematics - Combinatorics, Algebraic Topology (math.AT), Eilenberg-MacLane spaces, Mathematics - Algebraic Topology, Combinatorics (math.CO), Mathematics - Group Theory
Configurations and arrangements of linear subspaces, subspace arrangements, Group Theory (math.GR), Eilenberg-Mac Lane spaces, divisible partitions, Combinatorics of partially ordered sets, Group actions on combinatorial structures, Dowling lattices, Reflection and Coxeter groups (group-theoretic aspects), Combinatorial aspects of representation theory, reflection groups, ribbon representations, FOS: Mathematics, Mathematics - Combinatorics, Algebraic Topology (math.AT), Eilenberg-MacLane spaces, Mathematics - Algebraic Topology, Combinatorics (math.CO), Mathematics - Group Theory
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 1 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
