Speaker: Felix Goldberg (Technion)

Title: "Quasi Strongly Regular Graphs"

Abstract:
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The notion of strong regularity of graphs, introduced by Bose in 1963,
admits many interesting generalizations.  In this talk we will discuss
some of these generalizations and then focus our attention on the concept
of quasi-strong regularity (introduced by Golightly, Haynsworth and
Sarvate in 1997), a natural combinatorial generalization of strong
regularity.

Some new results on quasi-strongly regular graphs will be presented,
including an extension of Seidel's well-known eigenvalue formula for
strongly regular graphs and some constructions of quasi-strongly regular
graphs.  Open problems and conjectures will also be offered.