Graphs are everywhere. In discrete mathematics, they are structures that show the connections between points, much like a ...

Just five days after posting a retraction, László Babai announced that he had fixed the error in his landmark graph isomorphism algorithm. The back and forth ...

We show that the groupoids of two directed graphs are isomorphic if and only if the two graphs are orbit equivalent by an orbit equivalence that preserves isolated eventually periodic points. We also ...