English

Convolution dominated operators on compact extensions of abelian groups

Functional Analysis 2018-03-28 v2

Abstract

If GG is a locally compact group, CD(G)CD(G) the algebra of convolution dominated operators on L2(G)L^2(G) then an important question is: Is C1+CD(G)\mathbb{C}1+CD(G) (respectively CD(G)CD(G) if GG is discrete) inverse-closed in the bounded operators on L2(G)L^2(G)? In this note we answer this question in the affirmative provided GG is such that one of the following properties is fulfilled (1) There is a discrete, rigidly symmetric, and amenable subgroup HGH\subset G and a (measurable) relatively compact neighbourhood of the identity UU invariant under conjugation by elements of HH such that {hU  :  hH}\{hU\;:\;h\in H\} is a partition of GG. (2) The commutator subgroup of GG is relatively compact. (If GG is connected this just means that GG is an IN group.) All known examples where CD(G)CD(G) is inverse-closed in B(L2(G))B(L^2(G)) are covered by this.

Keywords

Cite

@article{arxiv.1711.08638,
  title  = {Convolution dominated operators on compact extensions of abelian groups},
  author = {Gero Fendler and Michael Leinert},
  journal= {arXiv preprint arXiv:1711.08638},
  year   = {2018}
}

Comments

14 pages, reformulated proof of proposition 4.5, an appendix on amenability added, corrected typos

R2 v1 2026-06-22T22:54:54.997Z