Exact solution of Schrödinger equation in (anti-)de Sitter spaces for hydrogen atom Mokhtar Falek, Noureddine Belghar and Mustafa Moumni Eur. Phys. J. Plus, 135 3 (2020) 335 Published online: 30 March 2020 DOI: 10.1140/epjp/s13360-020-00337-4