It is shown that for generic configuration of the centres at high energy
levels the n-centre problem is completely integrable by using $C^\infty$
integrals of the motion however it is not integrable in terms of real analytic
functions
@article{0312429,
author = {Knauf, A. and Taimanov, I. A.},
title = {Integrability of the n-centre problem at high energies},
journal = {arXiv},
volume = {2003},
number = {0},
year = {2003},
language = {en},
url = {http://dml.mathdoc.fr/item/0312429}
}
Knauf, A.; Taimanov, I. A. Integrability of the n-centre problem at high energies. arXiv, Tome 2003 (2003) no. 0, . http://gdmltest.u-ga.fr/item/0312429/