Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
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Claim. Let with every . Then contains a disk of radius about one of the zeros, so
the open set included, since every point of that disk has modulus below . This is Theorem 4 of Pommerenke, On metric properties of complex polynomials, Michigan Math. J. 8 (1961), no. 2, 97–115 (Theorem 4, printed p. 101), recorded on the result page [[../library/analysis/pommerenke_1961_metric_properties_complex_polynomials/theorem_4|Theorem 4]] of the card [[../library/analysis/pommerenke_1961_metric_properties_complex_polynomials/_index|Pommerenke 1961]]. It answers the question of Problem 116 yes: the area is at least , with exponent . The proof combines the diameter bound of the paper's Theorem 3 (the component through has diameter above , hence capacity above ) with the derivative bound on that component, and integrates from a zero to the nearest point of modulus . The parenthetical stronger form, an area of at least , is not covered by this claim; it is the subject of the accepted claim [[problems/polynomials/E0116/claims/2025_03_24_krishnapur_lundberg_ramachandran|Krishnapur, Lundberg and Ramachandran 2025]].
Depends on. No page of this wiki: the proof is self-contained in the paper.
Acceptance. Refereed: the paper appeared in the Michigan Mathematical Journal in 1961 (volume 8, issue 2; the issue carries no month, so the page's date is the first day of the publication year). Reviewed: erdosproblems.com labels the problem proved and states that the lower bound follows from this paper, cited as [Po61] (page last edited 2025-10-24), which the corpus counts as documented independent acceptance by the site's curator, T. F. Bloom (erdosproblems.com); the community database lists the problem as proved with a Lean marker (entry last updated 2026-08-24).
Formalization. The site's Lean marker refers to a formal proof by others,
with a different argument: the file linked above, in the lean-proofs
repository at the pinned commit, ends with Erdos116.erdos_116, which states
that there are and with
for every and
every with all , obtained with the explicit constants
and ; its docstring describes an elementary
reflected-polynomial and finite-Fourier argument rather than Pommerenke's, and
its header names Codex and GPT-5.6 Sol as formal authors and Christian
Pommerenke, this paper's author, as the informal author, which is why the file
is a link on this page and not a claim of its own. The formal-conjectures
statement of the problem is marked solved with a link to this declaration. The
development is unbuilt and unaudited against the question by this corpus, so
the evidence lists no formalized kind; the standing rests on the refereeing
and the site's acceptance.