Top Posts
Recent comments
Blogroll
 Astronomy Picture of the Day
 Azimuth
 British Combinatorial Committee
 Comfortably numbered
 Diamond Geezer
 Exploring East London
 From hill to sea
 Gödel's lost letter and P=NP
 Gil Kalai
 Jane's London
 Jon Awbrey
 Kourovka Notebook
 LMS blogs page
 Log24
 London Algebra Colloquium
 London Reconnections
 MathBlogging
 Micromath
 Neill Cameron
 neverendingbooks
 Noncommutative geometry
 numericana hall of fame
 Ratio bound
 Robert A. Wilson's blog
 Since it is not …
 Spitalfields life
 Sylvy's mathsy blog
 SymOmega
 Terry Tao
 The Aperiodical
 The De Morgan Journal
 The ICA
 The London column
 The Lumber Room
 The matroid union
 Theorem of the day
 Tim Gowers
 XKCD
Find me on the web

Join 664 other subscribers
Cameron Counts: RSS feeds
Meta
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
Leave a comment