Hostname: page-component-848d4c4894-pftt2 Total loading time: 0 Render date: 2024-06-08T13:02:53.770Z Has data issue: false hasContentIssue false

A Maximum Principle for Dirichlet-Finite Harmonic Functions on Riemannian Spaces

Published online by Cambridge University Press:  20 November 2018

Y. K. Kwon
Affiliation:
University of California, Los Angeles, California
L. Sario
Affiliation:
University of California, Los Angeles, California
Rights & Permissions [Opens in a new window]

Extract

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.

Representations of harmonic functions by means of integrals taken over the harmonic boundary ΔR of a Riemann surface R enable one to study the classification theory of Riemann surfaces in terms of topological properties of ΔR (cf. [6; 4; 1; 7]). In deducing such integral representations, essential use is made of the fact that the functions in question attain their maxima and minima on ΔR.

The corresponding maximum principle in higher dimensions was discussed for bounded harmonic functions in [3]. In the present paper we consider Dirichlet-finite harmonic functions. We shall show that every such function on a subregion G of a Riemannian N-space R attains its maximum and minimum on the set , where ∂G is the relative boundary of G in R and the closures are taken in Royden's compactification R*. As an application we obtain the harmonic decomposition theorem relative to a compact subset K of R* with a smooth (KR).

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1970

References

1. Chang, J., Roydens compactification of Riemannian spaces, Doctoral dissertation, University of California, Los Angeles, 1968.Google Scholar
2. Kwon, Y. K., Integral representations of harmonie functions on Riemannian spaces, Doctoral dissertation, University of California, Los Angeles, 1969.Google Scholar
3. Kwon, Y. K. and Sario, L., A maximum principle for bounded harmonie functions on Riemannian spaces, Can. J. Math. 22 (1970), 847854.Google Scholar
4. Nakai, M., A measure on the harmonie boundary of a Riemann surface, Nagoya Math. J. 17 (1960), 181218.Google Scholar
5. Royden, H., Harmonie functions on open Riemann surfaces, Trans. Amer. Math. Soc. 73 (1952), 4094.Google Scholar
6. Royden, H., On the ideal boundary of a Riemann surface, Ann. of Math. (2) 30 (1953), 107109.Google Scholar
7. Sario, L. and Nakai, M., Classification theory of Riemann surfaces (Springer-Verlag, New York, 1970).Google Scholar
8. Sario, L., Schiffer, M., and Glasner, M., The span and principal functions in Riemannian spaces, J. Analyse Math. 15 (1965), 115134.Google Scholar