Research interests
My primary mathematical interests are in
the field of groups, graphs and geometries.
I'm involved in the program of the classification
of finite primitive distance-transitive graphs.
My research has been mainly concentrated on
Distance-regular and Distance-transitive graphs
Sporadic finite simple groups and their geometries
Generalized polygons and their extensions
Permutation Groups
Locally s-transitive groups
Multiplicity-free permutation representations
Scientific meetings and summer schools
I've been a co-organizer of
Groups and Graphs, Amsterdam, 1989
Summer School on Finite groups and related Geometrical Structures, Udine, 2005
Summer School on Finite Groups and related Geometrical Structures, Dobbiaco-Toblach, 2006
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2007
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2008
Arjeh 60, Eindhoven, 2009.
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2010
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2011
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2013
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2015
Summer School on Finite Groups and related Geometrical Structures, Dobbiaco-Toblach, 2017
Summer School on Finite Groups and related Geometrical Structures, Venezia, 2019