Rocky Mountain Algebraic Combinatorics Seminar

Unravelling Primitivity

Alexander Hulpke

Every 2-transitive group is primitive, but not every primitive group is 2-transitive. Recent combinatorial definitions allow for a better analysis of the area between these two definitions. I will look at some of these definitions and consider ways how to test for them. This is joint work with Peter Cameron and Joao Araujo.


Graph Labelings and Computability Theory

Oscar Levin
University of Northern Colorado

A graph labeling assigns integers to vertices, edges, or both, subject to certain conditions. For example, a labeling is graceful if the difference of labels on adjacent vertices is distinct for all edges, while a labeling is edge-magic if the sum of the labels on an edge and its incident vertices is constant for all edges. Graph labelings are usually studied for finite graphs, but some work has been done to extend these to infinite cases. In this talk we will consider the computable analogues to some results for graceful, edge-magic, and related labelings of infinite graphs. Using ideas from computability theory, we will explore the connection between the complexity of a graph's presentation and the complexity of its labelings. We will share a few initial findings and many directions for future research.


Weber 223
4–6 pm
Friday, September 30, 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.

PDF version

Previous Seminars:

September 16, 2016
Delaram Kahrobaei, Amit Patel
June 23, 2016
Jason Cantarella, Michal Adamaszek
April 29, 2016
Nick Loehr, Jason Williford
April 15, 2016
Alexander Hulpke, Klaus Lux
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