Graph isomorphism: physical resources, optimization models, and algebraic characterizations

Laura Mančinska, David E. Roberson*, Antonios Varvitsiotis

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

34 Downloads (Pure)


In the (G, H)-isomorphism game, a verifier interacts with two non-communicating players (called provers), by privately sending each of them a random vertex from either G or H. The goal of the players is to convince the verifier that the graphs G and H are isomorphic. In recent work along with Atserias et al. (J Comb Theory Ser B 136:89–328, 2019) we showed that a verifier can be convinced that two non-isomorphic graphs are isomorphic, if the provers are allowed to share quantum resources. In this paper we model classical and quantum graph isomorphism by linear constraints over certain complicated convex cones, which we then relax to a pair of tractable convex models (semidefinite programs). Our main result is a complete algebraic characterization of the corresponding equivalence relations on graphs in terms of appropriate matrix algebras. Our techniques are an interesting mix of algebra, combinatorics, optimization, and quantum information.

Original languageEnglish
JournalMathematical Programming
Number of pages44
Publication statusPublished - 2023


Dive into the research topics of 'Graph isomorphism: physical resources, optimization models, and algebraic characterizations'. Together they form a unique fingerprint.

Cite this