The legendary graph isomorphism problem may be harder than a 2015 result seemed to suggest. “In Laci Babai, you have one of the most legendary and fearsome theoretical computer scientists there ever ...

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 ...

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

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 ...