Characterization of almost $L^p$-eigenfunctions of the Laplace-Beltrami operator

Pratyoosh Kumar, Swagato K. Ray, Rudra P. Sarkar

In \cite{Roe} Roe proved that if a doubly-infinite sequence $\{f_k\}$ of functions on $\mathbb{R}$ satisfies $f_{k+1}=(d{f}_k/dx)$ and $|f_k(x)|\le M$ for all $k=0,\pm 1,\pm 2,...$ and…