Institution: | (1) Department of Theoretical Physics, Palacky University, Tř. 17. listopadu 50, CZ-77207 Olomouc, Czech Republic;(2) Institute of Mathematics, Slovak Academy of Sciences, Štefánikova 49, SK-81473 Bratislava, Slovak Republic;(3) Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta, SK-84 228 Bratislava, Slovak Republic |