It has recently been shown that spherically symmetric potentials of finite
range are uniquely determined by the part of their phase shifts at a fixed
energy level $k^2>0$. However, numerical experiments show that two quite
different potentials can produce almost identical phase shifts. It has been
guessed by physicists that such examples are possible only for "less physical"
oscillating and changing sign potentials. In this note it is shown that the
above guess is incorrect: we give examples of four positive spherically
symmetric compactly supported quite different potentials having practically
identical phase shifts. The note also describes a hybrid
stochastic-deterministic method for global minimization used for the
construction of these potentials.
@article{0010033,
author = {Ramm, Alexander G. and Gutman, Semion},
title = {Piecewise-constant potentials with practically the same fixed-energy
phase shifts},
journal = {arXiv},
volume = {2000},
number = {0},
year = {2000},
language = {en},
url = {http://dml.mathdoc.fr/item/0010033}
}
Ramm, Alexander G.; Gutman, Semion. Piecewise-constant potentials with practically the same fixed-energy
phase shifts. arXiv, Tome 2000 (2000) no. 0, . http://gdmltest.u-ga.fr/item/0010033/