Local Λ sets for profinite groups

Michael Frank Hutchinson

Vol. 89 (1980), No. 1, 81–88

DOI: 10.2140/pjm.1980.89.81

Abstract

Let E be a subset of the dual Ĝ of a profinite group G. It is shown that if E is a local Λ set then the degrees of the elements of E must be bounded. It follows that Ĝ contains an infinite Sidon set if and only if Ĝ has infinitely many elements of the same degree. This characterisation is the same as one previously obtained for compact Lie groups.

Mathematical Subject Classification 2000

Primary: 43A46

Secondary: 20E18

Milestones

Received: 8 August 1978

Published: 1 July 1980