Some new constructions of imprimitive cometric association schemes
نویسندگان
چکیده
In a recent paper [9], the authors introduced the extended Q-bipartite double of an almost dual bipartite cometric association scheme. Since the association schemes arising from linked systems of symmetric designs are almost dual bipartite, this gives rise to a new infinite family of 4-class cometric schemes which are both Q-bipartite and Q-antipodal. These schemes, the schemes arising from linked systems, and all Q-polynomial bipartite distance-regular graphs enjoy a curious property: the relations restricted to any subcollection of the Q-antipodal classes is again a cometric association
منابع مشابه
Imprimitive cometric association schemes: Constructions and analysis
Dualizing the “extended bipartite double” construction for distance-regular graphs, we construct a new family of cometric (or Q-polynomial) association schemes with four associate classes based on linked systems of symmetric designs. The analysis of these new schemes naturally leads to structural questions concerning imprimitive cometric association schemes, some of which we answer with others ...
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