Functions in mathematics
This article is about harmonic functions in mathematics. For harmonic function in music, see
diatonic functionality.
A harmonic function defined on an annulus.
In mathematics, mathematical physics and the theory of stochastic processes, a harmonic function is a twice continuously differentiable function
where U is an open subset of
that satisfies Laplace's equation, that is,
everywhere on U. This is usually written as
or