English

Van der Corput's difference theorem for amenable groups and the left regular representation

Dynamical Systems 2024-10-25 v3 Representation Theory Spectral Theory

Abstract

We establish a connection between two variants of van der Corput's Difference Theorem (vdCDT) for countably infinite amenable groups GG and the ergodic hierarchy of mixing properties of a unitary representation UU of GG. In particular, we show that one variant of vdCDT corresponds to subrepresentations of the left regular representation, and another variant of vdCDT corresponds to the absence of finite dimensional subrepresentations. We then obtain applications for measure preserving actions of countably infinite abelian groups.

Keywords

Cite

@article{arxiv.2308.05560,
  title  = {Van der Corput's difference theorem for amenable groups and the left regular representation},
  author = {Sohail Farhangi},
  journal= {arXiv preprint arXiv:2308.05560},
  year   = {2024}
}

Comments

26 pages. This third edition is the journal edition. More referee comments have been incorporated, and the generality has been reduced from locally compact second countable amenable groups to countably infinite amenable groups

R2 v1 2026-06-28T11:52:48.180Z