### Top Posts

### Recent comments

- Ofir Gorodetsky on A little problem
- Ofir Gorodetsky on A little problem
- gorodetsky on A new constant?
- Ofir Gorodetsky on A little problem
- Peter Cameron on Andrzej Orchel

### Blogroll

- Alexander Konovalov
- Annoying precision
- Astronomy Picture of the Day
- Azimuth
- Bad science
- Bob Walters
- British Combinatorial Committee
- CIRCA tweets digest
- CoDiMa
- Coffee, love, and matrix algebra
- Collecting reality
- Comfortably numbered
- Computational semigroup theory
- DC's Improbable Science
- Diamond Geezer
- Exploring East London
- From hill to sea
- Gödel's lost letter and P=NP
- Gil Kalai
- Haris Aziz
- Intersections
- Jane's London
- Jon Awbrey
- Kourovka Notebook
- LMS blogs page
- Log24
- London Algebra Colloquium
- London Reconnections
- Marie Cameron's blog
- MathBlogging
- Micromath
- Neill Cameron
- neverendingbooks
- Noncommutative geometry
- numericana hall of fame
- Paul Goldberg
- Ratio bound
- Robert A. Wilson's blog
- Sheila's blog
- Since it is not …
- Spitalfields life
- St Albans midweek lunch
- Stubborn mule
- Sylvy's mathsy blog
- SymOmega
- Tangential thoughts
- 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
- Vynmath
- XKCD

### Find me on the web

### Cameron Counts: RSS feeds

### Meta

# Tag Archives: Pablo Spiga

## The Hall–Paige conjecture

A Latin square of ordern is an n×n array of symbols from an alphabet of size n with the property that each symbol in the alphabet occurs once in each row or column. Two Latin squares L and M are … Continue reading

## Synchronization update

There is some recent news about the synchronization project. Two steps forward have occurred. The set-up Here is a brief recapitulation. Let G be a transitive permutation group on Ω, where |Ω| = n. We say that G is non-synchronizing if there … Continue reading

## Summer school at Marienheide

Last week, I was lecturing at a summer school in Franz Dohrmann Haus, a very pleasant conference centre in the small town of Marienheide, not far from Köln. Apart from a walk on Wednesday afternoon, I didn’t get much exercise, … Continue reading

Posted in events
Tagged Cheryl Praeger, Csaba Schneider, O'Nan-Scott theorem, Pablo Spiga, permutation groups
Leave a comment

## Two publications

I don’t think it happened to me before that two of my papers were “published” on the same day. Fortunately, it didn’t happen on April Fools’ Day … One is my paper with Pablo Spiga on switching classes. I described … Continue reading

## Primitive switching classes

Last year I wrote here about switching classes of graphs for which the switching class has a primitive automorphism group. (I repeat the definitions briefly below.) I conjectured that, except for the trivial switching classes of the complete and null … Continue reading

Posted in exposition, mathematics
Tagged Akos Seress, Don Taylor, Pablo Spiga, primitive group, switching class, two-graph
Leave a comment

## Automorphism groups of hypergraphs

I am getting old and forgetful, but I don’t think I said anything here about this problem yet. If I did, apologies for the repetition – but there is something new to report! In April, Laci Babai and I finally … Continue reading

Posted in exposition, mathematics
Tagged Akos Seress, hypergraphs, Laci Babai, Pablo Spiga, primitive groups
Leave a comment