A partition theorem for a large dense linear order

M. Dzamonja; J. Larson; W. Mitchell

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arXiv · math/0506123

A partition theorem for a large dense linear order

M. Dzamonja·J. Larson·W. Mitchell

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Abstract

Let Q_K=(Q,<_Q)$ be a strongly K-dense linear order of size K for a suitable cardinal K. We prove, for all integers m > 1 that there is a finite value t_m^+ such that the set of all m-tuples from Q can be divided into t_m^+ many classes, such that whenever any of these classes C is colored with fewer than K many colors, there is a copy Q* of Q_K such that all m-tuples from Q* in C receive the same color. As a consequence we obtain that whenever we color the m-tuples of Q with fewer than K many colors, there is a copy of Q_K all m-tuples from which are colored in at most t_m^+ colors. In other words, the partition relation Q_K -->(Q_K)^m_{ 2 we have t_m^+ > t_m, the m-th tangent number. The paper also contains similar partition results about K-Rado graphs. A consequence of our work and some earlier results of Hajnal and Komjath is that a theorem of Shelah known to follow from a large cardinal assumption in a generic extension, does not follow from any large cardinal assumption on its own.

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BibTeX RIS

M. Dzamonja, J. Larson, W. Mitchell. 2005-06-07. A partition theorem for a large dense linear order. https://arxiv.org/abs/math/0506123

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