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Tag Archives: coherent configuration
A problelm
Given a finite permutation group G on a set X, the permutation character π of G is the function on G mapping an element g to its number of fixed points in X. This is a character of G, the … Continue reading
Proper Jordan schemes exist!
A new field of research has just been created by Misha Klin, Misha Muzychuk and Sven Reichard: proper Jordan schemes. They answered a question which I posed some time ago (I don’t remember when), about whether such objects exist. I … Continue reading
A problem
Since I have been saying rather a lot about association schemes and coherent configurations lately, I thought I would mention an open problem. This is probably one for the experts, and I guess it has been ignored because of the … Continue reading
Posted in open problems
Tagged association scheme, coherent configuration, permutation group
8 Comments
Terminology: association scheme or coherent configuration?
At the Villanova conference, many of the talks were about association schemes or coherent configurations, or indeed generalisations of these. A certain tension between different uses of these terms was evident. I’d like to set down my own views here. … Continue reading
Posted in exposition, history
Tagged association scheme, Bose, coherent configuration, Higman, Leman, Mesner, Nair, Schur ring, Shimamoto, Terwilliger, Weisfeiler
2 Comments