Numerical study of halo concentrations in dark-energy cosmologies K. Dolag, M. Bartelmann, F. Perrotta, C. Baccigalupi, L. Moscardini, M. Meneghetti and G. Tormen A&A, 416 3 (2004) 853-864 Published online: 09 March 2004 DOI: 10.1051/0004-6361:20031757