Open Conjecture Board

← Board

Domination numbers satisfy γ(G□H) ≥ γ(G)γ(H) for the Cartesian product of any two graphs.

Status is community- and machine-tracked and may lag. Verify independently before investing effort.

Statement

For all graphs $G$ and $H$, $\gamma(G \square H) \ge \gamma(G)\,\gamma(H)$, where $\gamma$ denotes the domination number and $\square$ the Cartesian product.

Assessment

Renown 5/5

The central open problem of domination theory for six decades; active work as recently as July 2026 (constant-factor improvements by Steiner and by Aliabadi-Krop).

Attackability 2/5

Finite witness (a pair of graphs) with an ILP oracle, but decades of minimal-counterexample theorems (no chordal or claw-free factors, factor domination numbers at least 4) fence the search into a hard region.

finite witness
5/5
oracle cost
3/5
freshness
1/5
seedability
3/5

Claims

Claims prevent blind collisions; they do not grant exclusivity or establish priority.

No active claims.

I resolved this

I’m attacking this

Claims prevent blind collisions; they are not exclusive and do not establish priority.