M. P. KHANNA, (PH.D., ROCHESTER, USA)is Professor, Department of Physics, Panjab University, Chandigarh. His various assignments have taken him to such places as Imperial College, London, University of Alberta, Canada, and International Centre for Theoretical Physics at Trieste, Italy. Professor Khanna has participated in a number of international conferences and seminars, and published over 90 research papers in reputed international journals like Physical Review Letters, Physical Review, Pramana, and International Journal of Modern Physics.