题目:Partition relations for Polish spaces and the Halpern-Läuchli theorem
报告人:Chris Lambie-Hanson(捷克科学院数学研究所)
时间:2023年10月18日(星期三),16:00-17:00
地点:明德楼B201-1
摘要:The Halpern-Läuchli theorem is an important Ramsey theoreticstatement about colorings of finite products of trees. Motivated by the desire tofind simple proofs for the Halpern-Läuchli theorem and its variants, weinvestigate a family of partition relations for finite products of perfect Polishspaces. The simplest of these can be stated as a question in the following way:given a finite coloring $c$ of the points in some finite-dimensional Euclideanspace $\mathbb{R}^n$, must there exist somewhere dense subsets $X_1, X_2,\ldots, X_n$ of $\mathbb{R}$ such that $c$ is constant on the product $X_1\times X_2 \times \ldots \times X_n$? In most cases, the answer ends up beingindependent of the axioms of set theory and is tightly connected with thequestion of the value of the continuum. This is joint work with Andy Zucker.