MathOverflow is a question and answer site for professional mathematicians. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

is any strongly regular graph a regular two-graph?

two-graph:a two graph is a collection $B$ of 3-subsets a set $X$ with the property that, for any 4-subset $Y$ of $X$, an even numbers of $B$ belong to $Y$.

regular two-graph:a two-graph is regular if it is a 2-design (with parameters $2-(n,3,\lambda)$ for some $\lambda$ )

share|cite|improve this question
up vote 6 down vote accepted

No, there is a correspondence between certain strongly regular graphs and two-graphs but those strongly regular graphs have specific and restricted parameters.

share|cite|improve this answer

ok, that's right, if $\Gamma$ is strongly regular graph with parameters $(v,k,\lambda,\mu)$ then it's regular two-graph if and only if $k=2\mu$

share|cite|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.