Extensions of Compact Abelian Groups by Discrete Ones and Their Duality Theory, II

A locally compact abelian group L is called selfdual if there exists an isomorphism ∇ : L → L ^ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429187605/d46d5034-f914-41b4-a96f-9f0731bff786/content/eq1511.tif"/> from L to its character group (see [ 6, 4, 5, 10, 11 ]).