1. Department of Mathematics, Shivagangotri, Davangere University, Davangere 577007, India
2. Department of Mathematics, Government Degree College, Chodavaram, Andhrapradesh 531036, India
3. Departamento de Física, FACI, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile
4. Instituto de Alta Investigación, CEDENNA, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile