Is it known what fraction (almost all?) of graphs have a trivial endomorphism monoid? I can't seem to find any reference to the question. Maybe it's related to the question: what fraction of graphs have chromatic number equal to their clique number?
1 Answer
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The book "Graph Homomorphisms" contains an elegant proof that a random graph admits only the identity endomorphism.
The term to search on is "rigid graph". (This has two different meanings but they are easy to distinguish.)
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$\begingroup$ Is this the book? Graphs and Homomorphisms amazon.com/… $\endgroup$ Commented Dec 14, 2014 at 17:58
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$\begingroup$ Yes, that's it. I also think that if you google a bit you might find some notes online giving the proof. $\endgroup$ Commented Dec 14, 2014 at 23:02