New posts in Eigenfunctions

Umbral calculus - eigenfunctions of operator

If $f$ is in the span of eigenfunctions, then $|f|$ is also in the span of eigenfunctions.

How to find Sturm-Liouville problem eigenvalue and function?

What functions can be represented as a series of eigenfunctions

Proving that the eigenfunctions of the Laplacian form a basis of $L^2(\Omega)$ (and of $H_0^1(\Omega)$)

Sturm Liouville with periodic boundary conditions

Proof that Legendre Polynomials are Complete