加载中…
M. Beiglb"ock, V. Bergelson, and A. Fish proved that if is a countable amenable group and and are subsets of with positive Banach density, then the product set is piecewise syndetic. This means that there is a finite subset of such that is thick, that is, contains translates of any finite subset of . When , this was first proven by R. Jin. We prove a quantitative version of the aforementioned result by providing a lower bound on the density (with respect to a F\o lner sequence) of the set of witnesses to the thickness of . When , this result was first proven by the current set of authors using completely different techniques.

生成讲解博客的中文版本

生成AI智能校验的中文版本