Wightman function and the Casimir effect for a Robin sphere in a constant curvature space S. Bellucci, A. A. Saharian and N. A. Saharyan Eur. Phys. J. C, 74 9 (2014) 3047 Published online: 11 September 2014 DOI: 10.1140/epjc/s10052-014-3047-4