Representing Measures and Hardy Spaces for the Infinite Polydisk Algebra
Representing Measures and Hardy Spaces for the Infinite Polydisk Algebra
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DOI:
10.1112/plms/s3-53.1.112
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发表时间:
1986-07
影响因子:
1.8
通讯作者:
B. Cole;T. Gamelin
中科院分区:
文献类型:
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作者:
B. Cole;T. Gamelin
Representing measures and Jensen measures are studied for the uniform algebra on the infinite polydiskgenerated by the coordinate functions z1z2,…. Let σ be the Haar measure on the infinite torusT∞, which is the distinguished boundary of the infinite polydisk. For fixedpin the range 1 <p, < ∞, it is shown that a point ζ ∈ Δ∞ has a representing measure inLP(σ) if and only if ζ ∈l2. A related result for a class of representing measures for the origin, including the Haar measure σ, and for fixed p in the range 0 <p< ∞, is that the point evaluation at ζ is continuous in theLp-norm if and only if ζ ∈ Δ∞ ∩l2. In this case the functions inHpare shown to correspond to analytic functions on the domain Δ∞l2inl2. Along these same lines, it is shown thatH∞ (σ) is isometrically isomorphic toH(Δ∞ ∩l2), and also toH∞(B), whereBis the open unit ball of the sequence spacec0.