Tag Archives: Sierpinski’s onto mapping principle

Was Ulam right? I: Basic theory and subnormal ideals

Joint work with Tanmay Inamdar. Abstract. We introduce various coloring principles which generalize the so-called onto mapping principle of Sierpinski to larger cardinals and general ideals. We prove that these principles capture the notion of an Ulam matrix and allow … Continue reading

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Ramsey theory over partitions III: Strongly Luzin sets and partition relations

Joint work with Menachem Kojman and Juris Steprāns. Abstract.  The strongest type of coloring of pairs of countable ordinals, gotten by Todorcevic from a strongly Luzin set, is shown to be equivalent to the existence of a nonmeager set of … Continue reading

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Jones’ theorem on the cardinal invariant p

This post continues the study of the cardinal invariant p. We refer the reader to a previous post for all the needed background. For ordinals α,α0,α1,β,β0,β1, the polarized partition relation (αβ)(α0α1β0β1) asserts that for every coloring f:α×β2, (at least) … Continue reading

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