题目：Iterated star map and its applications to combinatorics
报告人：Renling Jin（查尔斯顿大学）
时间：2024年5月16日（星期二），14:00-15:00
地点：明德楼B201-1报告厅
摘要：A star map is a bounded elementary embedding from a superstructure V(X) to another superstructure V(Y) where X is a subset of Y. Star map is an important tool in nonstandard analysis which connects standard mathematics to nonstandard mathematics. In this talk, we establish a framework where the star map is actually an embedding from V(X) into V(X) itself. Hence, the map can naturally be iterated. Furthermore, the iteration can be conducted externally as well as internally with distinct merits, respectively. We will demonstrate the strength of this approach by proving some theorems in combinatorics in the framework. This is an on-going joint work with Mauro Di Nasso.
