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Tag Archives: coherent configurations
Peter Neumann’s 3p paper
In 1955, Helmut Wielandt published a paper proving the following theorem: Let G be a primitive permutation group of degree 2p, where p is a prime greater than 3, which is not doubly transitive. Then p = 2a2+2a+1 for some positive integer … Continue reading
G2D2, 2: first week
The campus of the China Three Gorges Hotel has a small river, full of waterlilies and lotus flowers. Beside it runs a main road, along which big water trucks run, shooting atomised water from cannonlike structures; we are told this … Continue reading
Pilsen, days 1 and 2
The conference on “Symmetry vs Regularity” in Pilsen has begun. I hesitate at trying to describe the talks, since the first day alone had 13 talks, and the second day 19, of lengths ranging from ten minutes to an hour, … Continue reading
Symmetry vs Regularity
This is the title of a conference to be held next year (2018) from 1 to 7 July, in Pilsen, Bohemia, Czech Republic. The subtitle is “The first 50 years since WeisfeilerLeman stabilization”, and the webpage is here. If you … Continue reading
Asymptotic group theory, 4
Thursday was a national holiday in Hungary, St Stephen’s Day if you are religious or traditional, Constitution Day if you are a communist. “The shrewd communists let the parliament pass the new constitution on August 20, 1949,” in the words … Continue reading
Posted in events, exposition
Tagged alternating groups, black box groups, coherent configurations, fireworks, St Stephen
1 Comment
Busy times, 8: Algebraic graph theory at Villanova
This week, five time zones to the west; next week, three to the east. This week was Andrew Woldar’s conference on algebraic graph theory at Villanova University, a Catholic school founded by Irish Augustinian friars in about 1850. I had … Continue reading
Posted in events
Tagged association schemes, coherent configurations, maps, Philadelphia, Qpolynomial
1 Comment
Synchronizing coherent configurations
In previous posts I have discussed coherent configurations and synchronization. Yesterday I realised that these two topics can be combined … Synchronization A (finitestate, deterministic) automaton consists of a finite set of states and a finite set of transitions, each … Continue reading
Posted in exposition, history
Tagged Boris Weisfeiler, coherent configurations, permutation groups, synchronization
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