FormalConjectures/ErdosProblems/161.lean
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2 declarations, 2 contain sorry, 0 declared as axioms
Erdős Problem 161
References:
- erdosproblems.com/161
- [CFS11] Conlon, David and Fox, Jacob and Sudakov, Benny, Large almost monochromatic subsets in hypergraphs. Israel J. Math. (2011), 423--432.
- [Er90b] Erdős, Paul, Problems and results on graphs and hypergraphs: similarities and differences . Mathematics of Ramsey theory (1990), 12-28.
Imports (1)
- theorem
Erdos161.erdos_161.parts.iLet $\alpha\in[0,1/2)$ and $n,t\geq 1$ sorry line 48 sourceSource documentation
Let $\alpha\in[0,1/2)$ and $n,t\geq 1$. Let $F^{(t)}(n,\alpha)$ be the smallest $m$ such that we can $2$-colour the edges of the complete $t$-uniform hypergraph on $n$ vertices such that if $X\subseteq [n]$ with $\lvert X\rvert \geq m$ then there are at least $\alpha \binom{\lvert X\rvert}{t}$ many $t$-subsets of $X$ of each colour. For fixed $n,t$ as we change $\alpha$ from $0$ to $1/2$ does $F^{(t)}(n,\alpha)$ increase continuously or are there jumps? Only one jump?
Here growth is compared up to constant factors as $n\to\infty$. At $\alpha=0$, each color must occur, following the source's Ramsey convention.
depends on sorry what this means
Statement uses:
Nat,Set,Prod,Real,sorryAx,Bool.false,LE.le,OfNat.ofNat,Eq,Set.ofPred,And,Membership.mem,Set.Ico,HDiv.hDiv,Prod.fst,Prod.snd,Asymptotics.IsTheta,Filter.atTop, Hypergraph.balancedColoringThresholdProof uses:
Lean.Name,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous36 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_161.parts.i : let E : ℕ → Set (ℝ × ℝ) := answer(sorry) … - theorem
Erdos161.erdos_161.parts.iiFor fixed $t\geq 3$, do all positive densities below $1/2$ give the same asymptotic order? sorry line 60 sourceSource documentation
For fixed $t\geq 3$, do all positive densities below $1/2$ give the same asymptotic order?
depends on sorry what this means
Statement uses:
Iff,True,Nat,LE.le,OfNat.ofNat,Real,LT.lt,HDiv.hDiv,Asymptotics.IsTheta,Filter.atTop, Hypergraph.balancedColoringThresholdProof uses:
sorryAx,Lean.Name,Bool.false,Lean.Name.num,Lean.Name.str,Lean.Name.anonymous34 instances, coercions and auxiliary constants left out.
Tactic trace: 1 steps
Open to load the checked before-and-after goal states.
theorem erdos_161.parts.ii : answer(sorry) ↔ ∀ t : ℕ, 3 ≤ t → ∀ α β : ℝ, 0 < α → α < 1 / 2 → 0 < β → β < 1 / 2 → (fun n ↦ (Hypergraph.balancedColoringThreshold n t α : ℝ)) =Θ[atTop] (fun n ↦ (Hypergraph.balancedColoringThreshold n t β : ℝ)) := by …Mentions: Hypergraph.balancedColoringThreshold