### Top Posts

### Recent comments

- Asghar Moeini on The Traveling Salesman Problem: An Optimization Model
- Peter Cameron on Beginning a career
- Josh Paik on Beginning a career
- David Roberts on Combinatorial Theory
- Rick Thomas on The Fitting subgroup

### 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: Cayley graphs

## 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 cannon-like structures; we are told this … Continue reading

## Normal

There are various overused terms in mathematics. “Normal” is one of them. Perhaps the four commonest uses are the following: A complex square matrix is normal if it commutes with its conjugate transpose. Normal matrices are precisely the ones which … Continue reading

Posted in exposition
Tagged Cayley graphs, field extensions, groups, matrices, terminology, topological spaces
3 Comments

## A Cayley graph challenge

Greg Cherlin showed that Henson’s graphs are Cayley graphs, so perhaps it is time to look again at the question: Is Covington’s graph a Cayley graph? Here, to start things off, is a simple fact: Covington’s graph G is not … Continue reading

## The sound of problems falling

This month brought news that two problems I posed have been solved. A conjecture of mine was proved by Martin Bridson and Henry Wilton, and another question (which I didn’t feel brave enough to connjecture) has been answered by Greg … Continue reading

## London Combinatorics Colloquia, 2

It’s that time of year again, and while I miss the buttercups in Reading, we had as usual a feast of interesting mathematics and a large and enthusiastic audience. It was a bit more tightly focussed than I would have … Continue reading

Posted in events, exposition
Tagged amenability, Ben Green, Cayley graphs, Endre Szemeredi, Gabor Kun, Noga Alon, Norman Biggs, Regularity Lemma, sum-free sets
Leave a comment