Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-12-01T02:50:31.206Z Has data issue: false hasContentIssue false

Variation formulas for principal functions, II: Applications to variation for harmonic spans

Published online by Cambridge University Press:  11 January 2016

Sachiko Hamano
Affiliation:
Department of Mathematics, Faculty of Human Development and Culture Fukushima University, Fukushima 960-1296, [email protected]
Fumio Maitani
Affiliation:
2-7-7 Hiyoshidai, Ohtsu Shiga 522-0112, [email protected]
Hiroshi Yamaguchi
Affiliation:
2-6-20-3 Shiromachi, Hikone Shiga 522-0068, [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A domain D ⊂ Cz admits the circular slit mapping P(z) for a, bD such that P(z) – 1/(za) is regular at a and P(b) = 0. We call p(z) = log|P(z)| the Li-principal function and α = log |P′(b)| the L1-constant, and similarly, the radial slit mapping Q(z) implies the L0-principal function q(z) and the L0-constant β. We call s = αβ the harmonic span for (D, a, b). We show the geometric meaning of s. Hamano showed the variation formula for the L1-constant α(t) for the moving domain D(t) in Cz with tB:= {t ∈ C: |t| < ρ}. We show the corresponding formula for the L0-constant β (t) for D(t) and combine these to prove that, if the total space D =tB(t, D (t)) is pseudoconvex in B × Cz, then s(t) is subharmonic on B. As a direct application, we have the subharmonicity of log cosh d(t) on B, where d(t) is the Poincaré distance between a and b on D(t).

Keywords

Type
Research Article
Copyright
Copyright © Editorial Board of Nagoya Mathematical Journal 2011

References

[1] Ahlfors, L. V. and Sario, L., Riemann Surfaces, Princeton Math. Ser. 26, Princeton University Press, Princeton, 1960.Google Scholar
[2] Bedford, E. and Gaveau, B., Envelopes of holomorphy of certain 2-spheres in C2 , Amer. J. Math. 105 (1983), 9751009.CrossRefGoogle Scholar
[3] Behnke, H., Die Kanten singuärer Mannigfaltigkeiten, Abh. Math. Semin. Univ. Hambg. 4 (1926), 347365.CrossRefGoogle Scholar
[4] Brunella, M., Subharmonic variation of the leafwise Poincaré metric, Invent. Math. 152 (2003), 119148.CrossRefGoogle Scholar
[5] Ford, L., Automorphic Functions, 2nd ed., Chelsea Publishing, New York, 1951.Google Scholar
[6] Grunsky, H., Neue Abschätzungen zur konformen Abbildung ein- und mehrfach zusam-menhängender Beriche, Schr. Sem. Univ. Berlin 1 (1932), 95140.Google Scholar
[7] Gunning, R. and Narasimhan, R., Immersion of open Riemann surfaces, Math. Ann. 174 (1967), 103108.Google Scholar
[8] Hamano, S., A lemma on C1 subharmonicity of the harmonic spans for the discontinuously moving Riemann surfaces, preprint to appear in J. Math. Soc. Japan.Google Scholar
[9] Hamano, S., Variation formulas for L1-principal functions and application to simultaneous uniformization problem, Michigan Math. J. 60 (2011), 271288.Google Scholar
[10] Hamano, S., Variation formulas for principal functions, III: Applications to variation for Schiffer spans, preprint.Google Scholar
[11] Levenberg, N. and Yamaguchi, H., The metric induced by the Robin function, Mem. Amer. Math. Soc. 448 (1991), 1155.Google Scholar
[12] Maitani, F. and Yamaguchi, H., Variation of Bergman metrics on Riemann surfaces, Math. Ann. 330 (2004), 477489.CrossRefGoogle Scholar
[13] Nakai, M. and Sario, L., Classification Theory of Riemann Surfaces, Grundlehren Math. Wiss. 164, Springer, New York, 1970.Google Scholar
[14] Nishimura, Y., Immersion analytique d’une famille de surfaces de Riemann ouverts, Publ. Res. Inst. Math. Sci. 14 (1978), 643654.Google Scholar
[15] Nishino, T., Function Theory in Several Complex Variables, Transl. Math. Monogr. 193, Amer. Math. Soc., Providence, 2001.Google Scholar
[16] Schiffer, M., The span of multiply connected domains, Duke Math. J. 10 (1943), 209216.CrossRefGoogle Scholar
[17] Yamaguchi, H., Variations of pseudoconvex domains over Cn , Michigan Math. J. 36 (1989), 415457.Google Scholar