Professor Patric R. J. Östergård's home page

If you want to contact me, see this page.

The University of Pécs conferred the degree of "Doctor et Professor Honoris Causa" on me at a ceremony held in Pécs, Hungary, on 7 November 2013.

Research interests

I am interested in a wide variety of problems in mathematics, telecommunications, and computer science. In particular, I am interested in using computers to find and classify mathematical objects. My research themes can roughly be divided into the following groups:

Recent and old news

The monograph Classification Algorithms for Codes and Designs, co-authored with Petteri Kaski, is to be found in a bookshop near you.

Some sporadic results:

This is an old one: There are 11,084,874,829 Steiner triple systems of order 19; see a paper by Petteri Kaski and myself.

There are 5983 perfect binary one-error-correcting codes of length 15; see the paper.

Together with Sampo Niskanen, we have developed Cliquer, routines for clique searching. The first public release (1.0) was made in late 2002; the current release (1.21) can be found here.

I am a recipient of the 1996 Kirkman Medal, awarded by The Institute of Combinatorics and its Applications.

I am co-Editor-in-Chief of the Journal of Combinatorial Designs.

My research is financed in part by the Academy of Finland.

I spent the year 1996 at the Department of Mathematics and Computing Science, Eindhoven University of Technology, the Netherlands. I spent the spring 2010 at the University of Bayreuth, Germany.


Here are (in pdf) some recent papers that have been accepted for publication. I also maintain a list of all my publications.

Planar hypohamiltonian graphs on 40 vertices, M. Jooyandeh, B. D. McKay, P. R. J. Östergård, V. H. Pettersson, and C. T. Zamfirescu, Journal of Graph Theory, to appear.
Total domination of grid graphs, S. Crevals and P. R. J. Östergård, Journal of Combinatorial Mathematics and Combinatorial Computing, to appear.
New lower bounds for the Shannon capacity of odd cycles, K. A. Mathew and P. R. J. Östergård, Designs, Codes and Cryptography, to appear.
On the domination number of 2-dimensional torus graphs, S. Crevals and P. R. J. Östergård, Utilitas Mathematica, to appear.
Classification of cyclic Steiner quadruple systems, Y. Chang, B. Fan, T. Feng, D. F. Holt, and P. R. J. Östergård, Journal of Combinatorial Designs, to appear.

Other interests

A marathon race takes only a little bit more than 2 hours for the elite. That is far from being a real endurance sport. You have to increase the running distance beyond 100k to find out who really has endurance. I have myself taken part in marathons in different sports. I maintain a list of all marathons that I have completed. For other sports than running, I have listed events that are at least 50k.

Latest update: September 2, 2016.