Graham's Number - Context

Context

Graham's number is connected to the following problem in Ramsey theory:

Consider an n-dimensional hypercube, and connect each pair of vertices to obtain a complete graph on 2n vertices. Then colour each of the edges of this graph either red or blue.

What is the smallest value of n for which every such colouring contains at least one single-coloured complete subgraph on 4 coplanar vertices?

In 1971, Graham and Rothschild proved that this problem has a solution, N*, and gave as a bound 6 ≤ N*N, with N being a very large, explicitly defined number:, where in Knuth's up-arrow notation. The lower bound of 6 was later improved to 11 by Geoff Exoo in 2003, and to 13 by Jerome Barkley in 2008. Thus, the best known bounds for N* are 13 ≤ N*N.

Graham's number, G, is much larger than N:, where . This weaker upper bound for the problem, attributed to an unpublished work of Graham, was eventually published and named by Martin Gardner in Scientific American in November 1977.

Read more about this topic:  Graham's Number

Famous quotes containing the word context:

    The hard truth is that what may be acceptable in elite culture may not be acceptable in mass culture, that tastes which pose only innocent ethical issues as the property of a minority become corrupting when they become more established. Taste is context, and the context has changed.
    Susan Sontag (b. 1933)

    Parents are led to believe that they must be consistent, that is, always respond to the same issue the same way. Consistency is good up to a point but your child also needs to understand context and subtlety . . . much of adult life is governed by context: what is appropriate in one setting is not appropriate in another; the way something is said may be more important than what is said. . . .
    Stanley I. Greenspan (20th century)

    Among the most valuable but least appreciated experiences parenthood can provide are the opportunities it offers for exploring, reliving, and resolving one’s own childhood problems in the context of one’s relation to one’s child.
    Bruno Bettelheim (20th century)