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Erdős problem 1044

Let f(z)=∏i=1n(z−zi)∈C[x]f(z)=\prod_{i=1}^n(z-z_i)\in\mathbb{C}[x] where ∣zi∣≤1\lvert z_i\rvert\leq 1 for all ii. If Λ(f)\Lambda(f) is the maximum of the lengths of the boundaries of the connected components of {z:∣f(z)∣<1} \{ z: \lvert f(z)\rvert<1\} then determine the infimum of Λ(f)\Lambda(f).

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The source's own material, retained exactly.

4 retained statements36c6d0fef71a

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FormalConjectures/ErdosProblems/

1044.lean

Retained formal statement2 of 4

Tang also suggests that, if the degree nn is fixed, then the infimum over all such ff of degree nn is attained by fn(z)=zn−1f_n(z)=z^n-1.

FormalConjectures/ErdosProblems/1044.leanErdos1044.erdos_1044.variants.fixed_degree4 linesExact file
∀ (n : ℕ),  0 < n →    IsLeast {L | ∃ f, Erdos1044.IsAdmissible f ∧ f.natDegree = n ∧ Erdos1044.maxBoundaryLength f = L}      (Erdos1044.maxBoundaryLength (Polynomial.X ^ n - 1))
OpenStatement only, no proof