Radial Propagation Incoming: Spherical Bessel Functions

The incoming waves in the solutions of the wave-equation in spherical coordinates are described by spherical harmonics and spherical Bessel functions, as so called "regular solutions" R(r,phi,theta)=jn(kr)*Ynm(phi,theta). These are standing waves, as they are purely real. In the figure below, an animation of these functions is given for modes of the orders n=0...3.