5 papers · 1 filter
The association scheme on the set of flags of a finite generalized quadrangle
Francesco Colangelo, Giusy Monzillo, Alessandro Siciliano
In this paper, the association scheme defined on the flags of a finite generalized quadrangle is considered. All possible fusions of this scheme are listed, and a full description…
On the -polynomial property of the full bipartite graph of a Hamming graph
Blas Fernández, Roghayeh Maleki, Štefko Miklavič +1
The -polynomial property is an algebraic property of distance-regular graphs, that was introduced by Delsarte in his study of coding theory. Many distance-regular graphs admit t…
On combinatorial structure and algebraic characterizations of distance-regular digraphs
Giusy Monzillo, Safet Penić
Let denote a simple strongly connected digraph with vertex set , diameter , and let denote the set of distance- matrices of . L…
On Hoffman polynomials of -doubly stochastic irreducible matrices and commutative association schemes
Giusy Monzillo, Safet Penjić
Let denote a finite (strongly) connected regular (di)graph with adjacency matrix . The {\em Hoffman polynomial} of is the unique polynomial of smallest degre…
Classifying pseudo-ovals, translation generalized quadrangles, and elation Laguerre planes of small order
Giusy Monzillo, Tim Penttila, Alessandro Siciliano
We provide classification results for translation generalized quadrangles of order less or equal to , and hence, for all incidence geometries related to them. The results consi…