Ramsey theory over partitions I: Positive Ramsey relations from forcing axioms

Menachem Kojman, Assaf Rinot, Juris Steprāns

Research output: Contribution to journalArticlepeer-review


In this series of papers we advance Ramsey theory over partitions. In this part, a correspondence between anti-Ramsey properties of partitions and chain conditions of the natural forcing notions that homogenize colorings over them is uncovered. At the level of the first uncountable cardinal this gives rise to a duality theorem under Martin’s Axiom: a function p: [ω 1]2 → ω witnesses a weak negative Ramsey relation when p plays the role of a coloring if and only if a positive Ramsey relation holds over p when p plays the role of a partition. The consistency of positive Ramsey relations over partitions does not stop at the first uncountable cardinal: it is established that at arbitrarily high uncountable cardinals these relations follow from forcing axioms without large cardinal strength. This result solves in particular two problems from [CKS21].

Original languageAmerican English
JournalIsrael Journal of Mathematics
StateAccepted/In press - 1 Jan 2023

All Science Journal Classification (ASJC) codes

  • General Mathematics


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