University of Delaware
Discrete Mathematics Seminar

On the connectedness of the complement of a ball in distance-regular graphs
Sebastian Cioaba
University of Delaware
Friday, April 13, 2012
Ewing Hall 336 4.45 - 5.45 pm

Abstract: An important property of strongly regular graphs is that the subgraph induced by the vertices at distance 2 from any fixed vertex x (also called the second subconstituent of x) is always connected unless the strongly regular graph is complete multipartite. During the GAC5 Conference in August 2011, Brouwer has asked to what extent can this statement be generalized to distance-regular graphs. I will discuss our progress on this problem. This is joint work with Jack Koolen (POSTECH, South Korea).