Hello everyone,

There was a faculty meeting today so Charlie Cunningham's topology seminar will be held Wednesday in MSCS 422 at 3:30. Talk to Andy if you are interested in going out to lunch with the speaker. We will also take Charlie out for dinner at hideaway at 5:30.

Best,

Neil

Title: The Geometry of Outer Automorphism Groups of Universal Right-angled Coxeter Groups

Speaker: Charles Cunningham, Haverford College

Date: Mar 14, 2018

Time: 3:30 PM

Room: MSCS422

Abstract: We investigate the combinatorial and geometric properties of automorphism groups of universal right-angled Coxeter groups. McCullough-Miller space is a polyhedral complex which is virtually a geometric model for the outer automorphism group of a universal right-angled Coxeter group, Out(Wn). As it is currently an open question as to whether or not Out(Wn) is CAT(0) or not, it would be helpful to know whether McCullough-Miller space can always be equipped with an Out(Wn)-equivariant CAT(0) metric. We show that the answer is in the negative. This is particularly interesting as there are very few non-trivial examples of proving that a space of independent interest is not CAT(0).

Note the special date and time.

______________________

Neil R. Hoffman Assistant Professor Department of Mathematics 523 Math Science Building Oklahoma State University Stillwater, OK 74078-1058 405-744-7791 http://math.okstate.edu/people/nhoffman