Al.I. Cuza University, Department of Theoretical Physics, Iaxc5x9fi, Romania. soprisan@uno.edu|Al.I. Cuza University, Department of Theoretical Physics, Iaxc5x9fi, Romania. soprisan@uno.edu|Al.I. Cuza University, Department of Theoretical Physics, Iaxc5x9fi, Romania. soprisan@uno.edu