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Erdős problem 119

For unit-modulus complex numbers ziz_i, let pn(z)=∏i≤n(z−zi)p_n(z)=\prod_{i\le n}(z-z_i) and Mn=max⁡∣z∣=1∣pn(z)∣M_n=\max_{|z|=1}|p_n(z)|. Erdős's prize question: is there c>0c>0 with ∑k≤nMk>n1+c\sum_{k\le n} M_k > n^{1+c}?

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FormalConjectures/ErdosProblems/

119.lean

Retained formal statement1 of 3

Is it true that lim sup⁡Mn=∞\limsup M_n = \infty?

This is Problem 4.1 in [Ha74] where it is attributed to Erdős.

The weaker conjecture that lim sup⁡Mn=∞\limsup M_n=\infty was proved by Wagner [Wa80], who show that there is some c>0c>0 with Mn>(log⁡n)cM_n>(\log n)^c infinitely often.

FormalConjectures/ErdosProblems/119.leanErdos119.erdos_119.parts.i1 lineExact file
True ↔ ∀ (z : ℕ → ℂ), (∀ (i : ℕ), ‖z i‖ = 1) → Filter.limsup (fun n => ↑(Erdos119.M z n)) Filter.atTop = ⊤
SolvedStatement only, no proof