Computing Scattering Resonances

The question of whether it is possible to compute scattering resonances of Schr"odinger operators - independently of the particular potential - is addressed. A positive answer is given, and it is shown that the only information required to be known a priori is the size of the support of the potential. The potential itself is merely required to be ${\mathcal{C}}^1$. The proof is constructive, providing a universal algorithm which only needs to access the values of the potential at any requested point.