Skip to main content

1984 | OriginalPaper | Buchkapitel

The Dual of H(G)

verfasst von : D. H. Luecking, L. A. Rubel

Erschienen in: Complex Analysis

Verlag: Springer New York

Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.

search-config
loading …

We want to prove, as in the case of the disk, that H(G)* = H0(ℂ \ G). We first study the dual of C(G). We change our notation here and write L(f) = ∫ fdμ when L ∈ C(G)*. (For the reader unfamiliar with integration theory this is simply a change in notation: The left-hand side defines the right-hand side. There are two advantages to this notation. First, it is the notation in which research papers are written. Second, the reader can call upon her experience with integration for intuition. For the mathematically advanced reader: we are invoking the Riesz Representation Theorem for C(G)*.) We call μ the “measure” associated with L, and we may identify μ and L. The collection of all such μ is denoted M0(G), so that M0(G) = C(G)*. We also write L(f) = ∫ f(z)dμ(z) when it is necessary to indicate the independent variable. “Measures” have the same properties as continuous linear functionals (which is what they are); for reinforcement, we list them here. Given μ ∈ M0(G): i)∫ (f + g)dμ = ∫ fdμ + ∫ gdμ, f, g ∈ C(G).ii)∫ afdμ = a ∫ fdμ, f ∈ C(G), a ∈ ℂ.iii)If fn → f in C(G) then ∫ fndμ → ∫ fdμ.iv)There is a compact set K ⊆ G such that | ∫ fdμ | ≤ C‖f‖K for all f ∈ C(G).

Metadaten
Titel
The Dual of H(G)
verfasst von
D. H. Luecking
L. A. Rubel
Copyright-Jahr
1984
Verlag
Springer New York
DOI
https://doi.org/10.1007/978-1-4613-8295-9_9