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Viewing Version 3 of 'Harnack's principle'
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Title of object: Harnack's principle
Canonical Name: HarnacksPrinciple
Type: Theorem

Created on: 2005-01-22 10:02:39
Modified on: 2005-01-22 10:10:00

Creator: pahio
Modifier: pahio
Author: pahio

Classification: msc:31A05, msc:31B05, msc:31C05, msc:30F15

Preamble:

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Content:

If the functions \,$u_1(z)$, $u_2(z)$, ... are harmonic in the domain \,$G \subseteq\mathbb{C}$\, and
$$u_1(z) \leqq u_2(z) \leqq ...$$
in every point of $G$, then \,$\lim_{n\to\infty}u_n(z)$\, either is infinite in every point of the domain or it is finite in every point of the domain, in both cases uniformly in each \PMlinkname{closed}{ClosedSet} subdomain of $G$. \,In the latter case, the function \,$u(z) = \lim_{n\to\infty}u_n(z)$\, is harmonic in the domain $G$.