Helson and Lowdenslager
extended the classical F. and M. Riesz theorem as follows:
Let G be a compact abelian group with the ordered dual Ĝ. Let μ be a bounded
regular measure on G which is of analytic type. Then μa and μs are of analytic
type.
Doss extended this theorem for a LCA group with the algebraically ordered
dual. On the other hand, deLeeuw and Glicksberg obtained an analogous
result for a compact abelian group G such that there exists a nontrivial
homomorphism from Ĝ into R. In this paper, we prove that the theorem of
Helson and Lowdenslager is satisfied for a LCA group with partially ordered
dual.
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