Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-06-02T07:20:06.877Z Has data issue: false hasContentIssue false

Boundary behaviour of harmonic functions and solutions of parabolic systems

Published online by Cambridge University Press:  20 January 2009

N. A. Watson
Affiliation:
Department of Mathematics, University of Canterbury, Christchurch, New Zealand
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.

In [1], Calderón proved that, if u is a harmonic function on Rn × ]0, ∞[, and at each point ξ of a subset E of Rn, u is bounded in some cone with vertex (ξ, 0), then u has a nontangential limit at almost every point of E × {0}. The main result of this note is a stronger version of this theorem, in which the hypotheses remain unchanged but the nontangential limits in the conclusion are replaced by limits through the more general approach regions first considered by Nagel and Stein in [7].

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 1988

References

REFERENCES

1.Calderón, A. P., On the behaviour of harmonic functions near the boundary, Trans. Amer. Math. Soc. 68 (1950), 4754.CrossRefGoogle Scholar
2.Chabrowski, J., Representation theorems for parabolic systems, J. Austral. Math. Soc. (Ser. A) 32 (1982), 246288.CrossRefGoogle Scholar
3.Doob, J. L., Relative limit theorems in analysis, J. Anal. Math. 8 (1960/1961), 289306.CrossRefGoogle Scholar
4.Flett, T. M., On the rate of growth of mean values of holomorphic and harmonic functions, Proc. London Math. Soc. (3) 20 (1970), 749768.CrossRefGoogle Scholar
5.Friedman, A., Partial differential equations of parabolic type (Prentice-Hall, Englewood Cliffs, 1964).Google Scholar
6.Mair, B. A. and Singman, D., A generalized Fatou theorem, Trans. Amer. Math. Soc. 300 (1987), 705720.CrossRefGoogle Scholar
7.Nagel, A. and Stein, E. M., On certain maximal functions and approach regions, Advances Math. 54 (1984), 83106.CrossRefGoogle Scholar
8.Stein, E. M., Singular integrals and differentiability properties of functions (Princeton University Press, Princeton, 1970).Google Scholar
9.Watson, N. A., Parabolic limits of solutions of weakly coupled parabolic systems, J. Math. Anal. Appl. 95 (1983), 278283.CrossRefGoogle Scholar