The spherical harmonics are functions describing the angular dependence of many physical problems e.g solutions to the Schrödinger equation for the hydrogen atom.
If the latitiude is denoted by v and x= cosv then the equation is
(d/dx){(1 – x2)dPndx} + n(n+1)Pn = 0.
Pn is the spherical harmonics or the Legendre polynomials of degree n.
a more detailde description is found below: