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Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

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Claim. There is a universal constant c>0c>0 such that for every n≥1n\ge1 there is a graph G′G' on nn vertices of maximum degree at most three with

r^(G′)≥cnexp⁡(clog⁡n),\hat r(G')\ge cn\exp\bigl(c\sqrt{\log n}\bigr),

where r^\hat r is the size Ramsey number (the problem's R^\hat R). Since exp⁡(clog⁡n)→∞\exp(c\sqrt{\log n})\to\infty, no constant c(3)c(3) bounds r^(G′)\hat r(G') by c(3) nc(3)\,n along this family, so the statement fails at d=3d=3 (and at every exact maximum degree d≥3d\ge3 after adding a disjoint star K1,dK_{1,d}, an elementary remark of this corpus, not a statement of the paper). The construction modifies the Rödl--Szemerédi graphs, random binary trees closed by a random cycle on their leaves, and improves their n(log⁡n)1/60n(\log n)^{1/60} to nexp⁡(clog⁡n)n\exp(c\sqrt{\log n}). The theorem is paged at Theorem 1.1 of the library's source card, which reads arXiv v2 (22 July 2023; the arXiv record's comment reads "revised version, accepted in Combinatorica"); v1 was posted on 11 October 2022, the date this page is named by. The original disproof is the page Rödl and Szemerédi 2000.

Acceptance. Reviewed: the site's curator, T. F. Bloom, labels the problem DISPROVED and credits Tikhomirov with raising the lower bound for cubic graphs to nexp⁡(clog⁡n)n\exp(c\sqrt{\log n}) in the problem's commentary (page last edited 18 January 2026, accessed 2026-09-17); the curator is independent of the author. Refereed: On bounded degree graphs with large size-Ramsey numbers, Combinatorica 44 (2024), no. 1, 9--14, published online 21 August 2023 and in the February 2024 issue (the Crossref record). The journal text is not held and was not compared with arXiv v2, so locators are preprint pages. Draganić and Petrova's 2025 paper quotes the result as the best lower bound for maximum degree three.

Read depth. Claims checked: Theorem 1.1 (p. 1) was checked clause by clause, and Lemma 2.3 and Corollary 2.4 as statements; the proof (pp. 2--4) was not checked, and nothing is independently reviewed in this corpus. How large r^\hat r can be for cubic graphs, between this bound and n3/2+o(1)n^{3/2+o(1)}, is open and is not this problem's question.

Depends on. Nothing in this wiki; the result is the paper's own theorem.