Rocky Mountain Algebraic Combinatorics Seminar

Calculations with Matrix Groups over the Integers

Alexander Hulpke
Colorado State University

Abstract: For matrix groups over the integers, reduction by a modulus m is a fundamental algorithmic tool. I will investigate how it can be used to study such groups on the computer, to test finiteness or finite index. Particular emphasis is given to Arithmetic groups, that is subgroups of SLn(Z) or Spn(Z) of finite index. For determining such an index the structure of classical groups over residue class rings Z/mZ, and the representation theory of classical groups become the major tools. This is joint work with A. Detinko and D. Flannery (both NUI Galway)


The 3-modular Character Table of the Fischer Group Fi23

Klaus Lux
University of Arizona

We will illustrate the state of the art methods in computational modular representation theory of finite groups. We will primarily focus on the example of the 3-modular character table of the sporadic simple Fischer group Fi23. This table was computed jointly with L. Goergen and G. Hiss, both at RWTH Aachen University. We will also give an overview of the recent progress on the Modular Atlas Volume 2 and which open problems might be expected to be solved in the near future by applying the methods described in the talk.


Weber 223
4–6 pm
Friday, April 15, 2016
(Refreshments in Weber 117, 3:30–4 pm)
Colorado State University

This is a joint Denver U / UC Boulder / UC Denver / U of Wyoming / CSU seminar that meets biweekly. Anyone interested is welcome to join us at a local restaurant for dinner after the talks.

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Previous Seminars:

April 1, 2016
Eamonn O'Brien, Izabella Stuhl
February 19, 2015
James Wilson, Anton Betten
December 4, 2015
Maria Monks Gillespie, Dane Flannery
November 13, 2015
Richard Green, Tim Penttila
October 23, 2015
Christina Boucher, Sylvia Hobart
October 9, 2015
Josh Maglione, Ghodratollah Aalipour
September 25, 2015
Ross McConnell, Henry Adams
September 11, 2015
James B. Wilson, Tim Penttila
May 8, 2015
Amanda Schaeffer Fry, Peter Brooksbank
April 24, 2015
Heide Gluesing-Luerssen, Phil DeOrsey
March 6, 2015
Felice Manganiello, Eric Moorhouse
February 20, 2015
Anton Dzhamay, Anton Betten
February 6, 2015
Alexander Hulpke, Morgan Rodgers
December 5, 2014
Stefaan De Winter, Gretchen Matthews
November 14, 2014
Greg Coxson, Tom Dorsey
October 31, 2014
Octavio Paez Osuna, Sylvia Hobart
October 10, 2014
Takunari Miyazaki, Eric Moorhouse
September 26, 2014
Elissa Ross, Anton Betten
September 12, 2014
Petr Vojtěchovský, Alexander Hulpke
May 9, 2014
Philip DeOrsey, Tim Penttila
April 25, 2014
William J Martin, Jason Williford
April 11, 2014
Victor Pambuccian, George Shakan
March 7, 2014
Nathan Lindzey, Jens Harlander
February 21, 2014
Ross McConnell, Anton Betten
November 22, 2013
Justin Hughes, Josh Maglione

Department of Mathematics
Fort Collins, Colorado 80523