**SMS scnews item created by John Enyang at Mon 3 Dec 2012 0935**

Type: Seminar

Modified: Mon 3 Dec 2012 0938; Fri 7 Dec 2012 1158

Distribution: World

Expiry: 8 Dec 2012

**Calendar1: 7 Dec 2012 1205-1255**

**CalLoc1: Carslaw 175**

Auth: enyang@penyang.pc (assumed)

### Algebra Seminar

# Topology of eigenspace posets for unitary reflection groups

### Koonin

###### Friday 7th December, 12:05--12:55pm, Carslaw 175

###### Speaker:

Justin Koonin (University of Sydney)

###### Title:

Topology of eigenspace posets for unitary reflection groups

###### Abstract:

The eigenspace theory of unitary reflection groups, initiated by Springer and Lehrer, suggests that the following object is worthy of study: the poset of eigenspaces of elements of a unitary reflection group, for a fixed eigenvalue, ordered by the reverse of inclusion. We investigate topological properties of this poset. The new results extend the well-known work of Orlik and Solomon on the lattice of intersections of hyperplanes.

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After the seminar we will take the speaker to lunch.

See the Algebra Seminar web page for information about other seminars in the series.

John Enyang John.Enyang@sydney.edu.au