[1] UL, IST, Dept Fis, Ctr Astrofis Gravitacao CENTRA, Ave Rovisco Pais 1, P-1049001 Lisbon, Portugal
[2] Univ Vienna, Fac Phys, Gravitat Phys Grp, Boltzmanngasse 5, A-1090 Vienna, Austria
[3] Kharkov VN Karazin Natl Univ, Dept Phys & Technol, 4 Svoboda Sq, UA-61022 Kharkov, Ukraine
[4] Kazan Fed Univ, Inst Math & Mech, 18 Kremlyovskaya St, Kazan 420008, Russia