1. Department of Physics, Gurukul Kangri Vishwavidyalaya, Haridwar 249404, India
2. Kanoria PG Mahila Mahavidyalaya, Jaipur 302004, India
3. Centre for Theoretical Physics, Jamia Millia Islamia, New Delhi 110025, India
4. Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of Kwa-Zulu-Natal, Private Bag 54001, Durban 4000, South Africa