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School of Mathematics

Short Course

Partitioned Matrices, Interlacing Eigenvalues and Graphs
Willem H. Haemers
Tilburg University
Tilburg, The Netherlands

Abstract: For about 30 years, I have been using eigenvalue methods in getting information on combinatorial structures. The first results appeared in 1979 in my PhD thesis (see poster of combinatorics II). A major techniques is eigenvalue interlacing. This technique will be explained, along with several old and new applications. These application involve the (co)clique size, the chromatic number, the number of edges in a biclique, and perfect matchings.

Time:	Sat. May 6, 15:00-16:00 Mon. May 8, 15:00-16:00 Wed. May 10, 15:00-16:00
Place:	Lecture Hall, Niavaran Bldg., Niavaran Sqr., Tehran, Iran