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I am currently reading the recent preprint of Dodos, Kanellopoulos, Tyros, where the ambitiously short proof of Density Hales Jewett theorem is provided. The important ingredient is Graham-Rothschild theorem. The authors say that it follows from the HJ by some standard Ramsey arguments, but I can not find them myself, at least immediately. Is it written anywhere? Original paper of Graham and Rothschild looks too long for being used in "simple self-contained proof" of anything. Polymath's DHJ proof does not use GR at all, on first glance.

flag	asked Sep 28 at 12:02 Fedor Petrov 6,789●1●12●38

arxiv.org/pdf/1209.4986.pdf – Kristal Cantwell Oct 27 at 7:35

@Kristal, it is exactly the paper I mean. Now I asked its authors directly and got a satisfactory answer with references. – Fedor Petrov Oct 29 at 12:36

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Fedor: Could you share the answer you got? I am struggling with the same exact problem. – Joel Moreira Feb 15 at 20:14

"The coloring result we use is indeed a special case of the Graham-Rothchild theorem. We do not say much about it in the paper, since this staff is considered to be part of the folklore. In any case,here are some references. 1) A simple and self-contained proof of the full Graham-Rothchild theorem can be found in: H. J. Promel and B. Voigt, Graham-Rothschild parameter sets, "Mathematics of Ramsey Theory", Springer-Verlag, Berlin (1990), 113-149.See in particular, Section 4, page 128. 2) Another excellent reference is: R. McCutcheon, Elemental Methods in Ergodic Ramsey Theory, Lect" – Fedor Petrov Feb 22 at 21:33

T.Karageorgos · Answer 1 · 2012-10-14 09:04:21Z UTC

In Randall - McCutcheon's book "Elemental methods in ergodic Ramsey theory" a stronger version of GR's theorem is prooved about block subspaces (theorem 2.4.1). The only theorems you need in order to proove it is Hales-Jewett and Folkman's theorem (about finite unions which you can proove using Hales - Jewett theorem again).

Another proof is given in Graham - Rothschild -Spencer book about Ramsey theory using HJ and linear algebra.

Graham-Rothschild via Hales-Jewett

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