1. Senior Research Scholar, Dept. of Mathematics, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
2. Assistant Professor, Dept. of Basic Sciences and Humanities, International Institute of Information Technology Bhubaneswar, Odisha 751003, India.
3. Associate Professor, Dept. of Mathematics, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India (corresponding author).