96 citations · 283 across the 48 of their papers we have counts for
4 papers · 2 filters
A new characterization of the dual polar graphs
Zhi Qiao, Jack Koolen
In this paper we give a new characterization of the dual polar graphs, extending the work of Brouwer and Wilbrink on regular near polygons. Also as a consequence of our characteriz…
Edge-regular graphs with regular cliques
Gary R. W. Greaves, Jack H. Koolen
We exhibit infinitely many examples of edge-regular graphs that have regular cliques and that are not strongly regular. This answers a question of Neumaier from 1981.
Distance-regular graphs without 4-claws
Sejeong Bang, Alexander Gavrilyuk, Jack Koolen
We determine the distance-regular graphs with diameter at least and but without induced -subgraphs.
Partially metric association schemes with a multiplicity three
Edwin R. van Dam, Jack H. Koolen, Jongyook Park
An association scheme is called partially metric if it has a connected relation whose distance-two relation is also a relation of the scheme. In this paper we determine the symmetr…