Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
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Claim. For every and every there is a monic polynomial of some degree such that has at least connected components each of diameter at least . This is Theorem 1.1 of L. Huang, Many lemniscates with large diameter, arXiv:2509.11597, first posted 15 September 2025, with a source card in the library. The method (Sections 2.1--2.3) builds one explicit domain , bounded by the image of the circle under a shifted Joukowski map, which contains the segment and has logarithmic capacity exactly ; places inside a set of pairwise disjoint Jordan domains, each of diameter greater than , separated from one another and from the boundary of ; and applies the Hilbert lemniscate theorem to with an -neighborhood that has separated components and lies inside , obtaining a polynomial with after normalization. Since and the capacity of is for a polynomial of degree with leading coefficient , the leading coefficient of has modulus at least , and with is monic with , a rotation and dilation by that can only enlarge diameters. The author notes that the restriction is optimal by Pólya's projection bound. The theorem answers the question of Problem 511 in the negative, and the author adds that the problem had already been solved by Pommerenke, whose claim page records the 1961 theorem; the two constructions are independent. The paper states its theorem for the closed sublevel set, while the problem is posed for the open set .
Acceptance. The site's curator, Thomas Bloom, labels the problem
disproved and credits this paper as an independent proof of the negative
answer, the reviewed evidence. The paper is an arXiv preprint and no
journal publication of it has been identified, so no refereed evidence is
listed.
Depends on. Nothing beyond the cited paper.