1. Department of Physics “E. Pancini”, University of Naples “Federico II”, Naples, Italy
2. INFN Sezione di Napoli, Complesso Universitario di Monte Sant’Angelo, Edificio G, Via Cinthia, I-80126 Naples, Italy
3. Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Naples, Italy
4. Laboratory of Theoretical Cosmology, Tomsk State University of Control Systems, and Radioelectronics (TUSUR), 634050 Tomsk, Russia
5. Department of Mathematics, Faculty of Civil Engineering, VSB-Technical University of Ostrava, Ludvika Podeste 1875/17, 708 00 Ostrava-Poruba, Czech Republic