Written on the Wall II - Conjecture 198a #
Reference: E. DeLaVina, Written on the Wall II, Conjectures of Graffiti.pc
theorem
WrittenOnTheWallII.GraphConjecture198a.conjecture198a
{α : Type u_1}
[Fintype α]
[DecidableEq α]
[Nontrivial α]
(G : SimpleGraph α)
(h : G.Connected)
(hb : G.b ≤ 2 + G.averageEccentricity)
:
∃ (a : α) (b : α) (p : G.Walk a b), p.IsHamiltonian
WOWII Conjecture 198a
For a simple connected graph G, if b(G) ≤ 2 + ecc_avg(G), then G has a Hamiltonian path.
Here b(G) is the number of vertices in a largest induced bipartite subgraph, and
ecc_avg(G) is the average eccentricity of G.
A Hamiltonian path is a walk visiting every vertex exactly once.