Does anyone how to solve the problem
$$ \Delta u=0$$
with $u \in R^n$ and $u(x) \to 0$ as $|x| \to \infty$?
Is $u=0$ the only solution?
Many thanks.
2026-04-01 17:09:05.1775063345
Are harmonic functions ($\Delta u=0$) with compact support unique?
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