Welcome to MathOverflow

Question

2

Let $G$ and $Cay(A,S)$ be strongly regular graphs with the same parameters. Is it true that $G$ is a cayley graph?

edited Dec 21 at 13:50

Chris Godsil
5,694●1●8●22

asked Dec 21 at 10:40

Mohsen
179●6

Dima Pasechnik · Accepted Answer · 2012-12-21 10:51:34Z UTC

6

no, this is certainly not true. IIRC already on 25 vertices there is a family of 15 non-isomorphic s.r.g.'s with the same parameters, some of them Cayley graphs, some not: see http://www.win.tue.nl/~aeb/graphs/Paulus.html.

answered Dec 21 at 10:51

Dima Pasechnik
3,080●3●14

2

Latin square graphs (e.g. cs.yale.edu/homes/spielman/561/2009/lect23-09.pdf) will work; for each possible order there is a Cayley graph and (in general, $n\ge5$) examples that are not. – Chris Godsil Dec 21 at 13:48

3

For anyone who decides, as I did, to do a google search to find out the meaning of IIRC, ignore the entries on the "Illinois Interactive Report Card" and on the "International Integrated Reporting Council". – Lee Mosher Dec 21 at 15:41

3

It means "Isn't It Really Cool" – Brendan McKay Dec 23 at 10:53

Yes, Brendan, this would work too :-) – Dima Pasechnik Dec 23 at 15:03

Strongly regular cayley graphs

Remember to vote up questions/answers you find interesting or helpful (requires 15 reputation points)

1 Answer

You can accept an answer to one of your own questions by clicking the check mark next to it. This awards 15 reputation points to the person who answered and 2 reputation points to you.