# ODE with Bessel decay

Discussion in 'Mathematics' started by AMath91, Oct 8, 2018.

1. ### AMath91Guest

This is related to my previous question, but it is probably less scary and an expert in using Mathematica could figure out an answer easily.

I would like to estimate the asymptotic behaviour of the solution of the following ODE $$w''(r)+\frac{1}{r}w'(r)-k^{2}w(r)=-g(r)$$ where $g$ is a smooth positive function function satisfying $$g(r) = O\left(\frac{e^{-kr}}{\sqrt{r}}\right) \ \ \ \ \ r\to +\infty .$$

Assuming that $w(r)$ decays exponentially fast, is it true that w(r) has exactly the same asymptotic decay as g(r)?