New posts in Isomorphism Testing

A "subtle" isomorphism testing problem: $\mathbb{Z}\ltimes_{A} \mathbb{Z}^5\cong \mathbb{Z}\ltimes_{B}\mathbb{Z}^5$ or not?

Are regular graphs the hardest instance for graph isomorphism?

if two graphs have the same distinct eigenvalues, can we conclude that they are isomorphic?