Willem Haemers
I know all decimals of π, only the order is a problem
Major fields
Discrete mathematics, combinatorics, algebraic graph theory, finite geometry, design theory and coding theory.
Publications
Research portal Tilburg University; ResearchGate; arXiv.
Spectra of Graphs, with Andries E. Brouwer, textbook, Springer Universitext, 2012.
The Beauty of Discrete Mathematics, Asset Magazine 26 (2011) 16-19.
Discreet en Mooi, Inaugurele rede (inaugural speech in Dutch), September 4, 2009).
Toughness conjecture, A conjecture on the toughness of a graph; a lower bound in terms of the Laplacian spectrum.
Eigenvalue techniques in design and graph theory, Ph.D. thesis (1979).
An inequality for near hexagons, with Rudi Mathon, unpublished manuscript, 1979.
Editorial
Editor (former editor-in-chief) of The Electronic Journal of Combinatorics.
Former editor of Innovations in Incidence Geometry.
Former member of the editorial board of Designs, Codes and Cryptography.
Member of the advisory board of Publications de l'Institut Mathématique (Serbia).
Conferences and workshops
Combinatorics 2024, Carovigno, Italy, 3-7 June 2024
Graphs and Groups, Complexity and Convexity" Shijiazhuang, August 11-25, 2024
Other things and links
Reader with Addendum for a series of lectures on "Matrix techniques for strongly regular graphs and related geometries", given in Ghent (April 2000).
Videos of an advanced course on eigenvalue techniques in graph theory given in Barcelona (June 2011).
1. Interlacing; the appetizer. 2. More interlacing for the adjacency matrix. 3. Perfect matchings. 4. Regularity and spectral characterizations.
Aida Abiad, Andries E. Brouwer, Edwin van Dam, Ted Spence.
Address
Department of Econometrics and Operations Research,
P.O. Box 90153,
5000 LE Tilburg,
The Netherlands
Tel. +31-134662777
Fax +31-134663280
E-mail haemers at uvt dot nl