Product set phenomena for countable groups
Artikel i vetenskaplig tidskrift, 2015

We develop in this paper novel techniques to analyze local combinatorial structures in product sets of two subsets of a countable group which are "large" with respect to certain classes of (not necessarily invariant) means on the group. Our methods heavily utilize the theory of C*-algebras and random walks on groups. As applications of our methods, we extend and quantify a series of recent results by Jin, Bergelson-Furstenberg-Weiss, Beiglbock-Bergelson-Fish, Griesmer and Di Nasso-Lupini to general countable groups.


Additive combinatorics

Topological dynamics

Ergodic Ramsey theory

Random walks on groups


Martin Björklund

Chalmers, Material- och tillverkningsteknik, Avancerad oförstörande provning

A. Fish

Advances in Mathematics

0001-8708 (ISSN) 1090-2082 (eISSN)

Vol. 275 47-113