Published online by Cambridge University Press: 24 October 2008
1. Let ξ, η denote the rectangular Cartesian coordinates of a point in a plane. Let J (ξ, η) denote a harmonic function which is positive in the half-plane η > 0. In this paper, we first show (Theorem I) that every such function J determines a non-negative number d, and a bounded non-diminishing function G(x), such that
* For further information concerning this case, see a paper by the author in Proc. London Math. Soc. (2), 37 (1934), 338–82Google Scholar, Theorem XXIV.
* Cf. Verblunsky, , Proc. London Math. Soc. (2), 38 (1934), 125–57Google Scholar, Theorem A.
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* Cf. Hardy, Littlewood and Pólya, , Inequalities (1934), pp. 196–8.Google Scholar
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* Hardy, Littlewood and Pólya, loc. cit. 225, Theorem 346.