Rocky Mountain Algebraic Combinatorics Seminar

Upcoming Seminars Schedule

Synchronization, diagonal structures, and the Hall--Paige conjecture

Peter Cameron
University of St Andrews

I will begin by telling you some of the story of synchronization, an investigation of permutation groups that has its origins in automata theory and semigroup theory; this work is mainly with João Araújo, along with several others.

Synchronizing permutation groups are primitive, so it is natural to look at (a simplified form of) the O'Nan-Scott classification of primitive groups. One of the types we have to deal with is diagonal type. The problem has been almost completely solved for these; this uses the solution of the celebrated Hall-Paige conjecture concerning perfect mappings in groups by Stewart Wilcox, Anthony Evans and John Bray.
This analysis prompted a closer look at diagonal type. The wreath products and affine groups preserve well-known geometric or combinatorial structures; such structures are not so well understood for diagonal type. With Rosemary Bailey, Cheryl Praeger and Csaba Schneider, I have just managed to find a beautiful characterisation of the combinatorial structures that diagonal groups preserve, which is not even written down yet; but if the proof is still standing by the time of the talk I will tell you about it.



Online via Zoom, Meeting at 3:30pm, talk starting 4.00pm

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:

Apr 3, 2020
Alexander Hulpke,
Feb 28, 2019
Joseph Iverson, John Jasper
Jan 24, 2019
Jonathan Novak,
Dec 6, 2019
Brendon Rhoades, James Wilson
Nov 15, 2019
Joshua Grochow, Maria Gillespie
Nov 1, 2019
Eilidh McKemmie, Michael Epstein
Oct 11, 2019
Martin Kassabov, Eric Moorhouse
Sep 27, 2019
Alexander Hulpke, Tianjuan Xu
Sep 13, 2019
Laura Scull, Emily King
Sep 28, 2018
Farid Aliniaeifard, Brady Tyburski
Sep 7, 2018
James Wilson, Alexander Hulpke
Apr 20, 2018
Maria Monks Gillespie, Alistair Savage
Apr 6, 2018
Susan Hermiller, Nathaniel Thiem
March 23, 2018
Henry Tucker, Richard Green
March 2, 2018
Nik Ruskuc, Joshua Grochow
February 16, 2018
Hamidreza Chitsaz, Mark Lewis
February 2, 2018
James B. Wilson, Anton Betten
November 10, 2017
Michael Kinyon, Petr Vojt\v{e}chovsk\'y
October 20, 2017
Eric Moorhouse, William DeMeo
October 6, 2017
Spencer Gerhardt, Joshua Grochow
September 22, 2017
Amanda Schaeffer Fry, Henry Kvinge
September 8, 2017
Peter Mayr, James B. Wilson
May 5, 2017
Ferdinand Ihringer, Gavin King
April 21, 2017
Vladimir D. Tonchev, Morgan Rodgers
April 7, 2017
Jason Williford, Anton Betten
March 24, 2017
Isabella Novik, Peter Brooksbank
March 3, 2017
Jintai Ding, Curtis Bennett
February 17, 2017
Fatma Karaoglu, Eric Moorhouse
February 3, 2017
Tim Penttila, James B. Wilson
December 2, 2016
Jim Fowler, Andrew Kelley
November 11, 2016
Joseph Gersch, Joshua Maglione
October 28, 2016
John MacLaren Walsh, Henry Adams
October 14, 2016
JM Landsberg, James B. Wilson
September 30, 2016
Alexander Hulpke, Oscar Levin
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