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An Upper Bound for the Ramsey Numbers r(K3,G)

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main_theorem: Every graph with q edges and no isolated vertices has Ramsey number at most 2q plus one against a triangle.


Wayne Goddard and Daniel J. Kleitman, An Upper Bound for the Ramsey Numbers r(K3,G)r(K_3,G), Discrete Mathematics 125(1--3) (1994), 177--182, DOI 10.1016/0012-365X(94)90158-9.

Local artifact. The selected author-hosted manuscript has seven physical pages numbered 1--7 in the file. It is mapped to the published article above. The journal span 177--182 is bibliographic metadata; it is not a printed-page locator in this selected manuscript. No notice is printed in the author manuscript (its first and last pages read in full); the card records no source URL for the author-hosted copy, so no host terms could be read, and the publisher's page for the journal version (DOI 10.1016/0012-365X(94)90158-9) governs only that version, which is not held; the term is unstated.

The unnumbered main theorem on physical and numbered p. 1 states that every graph GG with qq edges and no isolated vertices satisfies

r(K3,G)≤2q+1.r(K_3,G)\leq2q+1.

The source says this settles Harary's conjecture and is best possible as a function of qq. Its note added in proof (p. 7) states that the result was obtained earlier and independently by A. F. Sidorenko by different means. Its proof, on physical and numbered pp. 2--6, is an induction on qq organized by the minimum degree of GG, with separate treatments of adjacent and independent minimum-degree vertices.

For Problem 570, this is exactly the k=3k=3 bound, since ⌊(3−1)/2⌋=1\lfloor(3-1)/2\rfloor=1. It holds for every qq, so it is stronger than the problem's sufficiently-large qualification in this case.

Bears on. #569 (the k=1k=1 case, c1=3c_1=3, unconditional); #570.

Results to transcribe.

  • Main theorem: If GG has qq edges and no isolated vertices, then r(K3,G)≤2q+1r(K_3,G)\leq2q+1.

Living verification. Needs review. The identity, selected-artifact page numbering, exact theorem, and proof span were checked in the author manuscript; no complete proof is supplied, reconstructed, or independently certified here.

No file of this source is held: no license on record permits its redistribution, and the card cites the edition it names above.