In mathematics, the spherical harmonics are an orthogonal set of solutions to Laplace's equation represented in a system of spherical coordinates. The solutions are generally expressed in terms of trigonometric functions and Legendre polynomials. This form comes from separation of variables once the Laplacian is written in the spherical coordinate system.
The spherical harmonic with parameters l, m can be written as:
where <math>P_\ell^m<math> are the associated Legendre polynomials.
Spherical harmonics are important in many theoretical and practical applications, particularly the computation of atomic electron configurations, and the approximation of the Earth's gravitational field and the geoid.
