Harmonic Function Theory pp 1-29 | Cite as

# Basic Properties of Harmonic Functions

Chapter

## Abstract

Harmonic functions, for us, live on open subsets of real Euclidean spaces. Throughout this book,
where Δ =

*n*will denote a fixed positive integer greater than 1 and Ω will denote an open, nonempty subset of**R**^{ n }. A twice continuously differentiable, complex-valued function*u*defined on Ω is*harmonic*on Ω if$$\Delta u \equiv 0$$

*D*_{1}^{2}+ ⋯ +*D*_{ n }^{2}and D_{ j }^{2}denotes the second partial derivative with respect to the*j*^{th}coordinate variable. The operator Δ is called the*Laplacian*, and the equation Δ*u*≡ 0 is called*Laplace’s equation*. We say that a function*u*defined on a (not necessarily open) set*E*⊂**R**^{ n }is harmonic on*E*if*u*can be extended to a function harmonic on an open set containing*E*.## Keywords

Power Series Harmonic Function Compact Subset Maximum Principle Dirichlet Problem
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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## Copyright information

© Springer Science+Business Media New York 2001