Erdős problem 1077
We call a graph -balanced (or -almost-regular) if the maximum degree is at most times the minimum degree.
Sources
FormalConjectures/ErdosProblems/
1077.lean
Retained formal statement
We call a graph -balanced (or -almost-regular) if the maximum degree is at most times the minimum degree.
Let and and be sufficiently large. If is a graph on vertices with at least edges, then must contain a -balanced subgraph on vertices with at least edges?
False ↔ ∀ ε > 0, ε < 1 → ∀ α > 0, α < 1 → ∀ᶠ (D : ℝ) in Filter.atTop, ∀ᶠ (n : ℕ) in Filter.atTop, ∀ (G : SimpleGraph (Fin n)), ↑G.edgeSet.ncard > ↑n ^ (1 + α) → ∃ H, H.coe.IsBalanced D ∧ ↑H.verts.ncard > ↑n ^ (1 - α) ∧ ↑H.edgeSet.ncard > ε * ↑H.verts.ncard ^ (1 + α)SolvedStatement only, no proof