Pankaj Sharan is a professor retired from the Department of Physics at Jamia Millia Islamia, New Delhi. His research interests are chiefly in quantum mechanics, quantum field theory and general relativity. Over a teaching career spanning four decades, he has taught courses on quantum mechanics, quantum field theory, classical mechanics, general relativity and mathematical physics. He is the author of the book Spacetime, Geometry and Gravitation (Birkhäuser, 2009).

• 1st edition: Position operators of non-relativistic quantum mechanics.- A bundle picture of quantum mechanics.- A beam of particles = a plane wave?.- Star-product formulation of quantum mechanics.- Can there be a non-linear quantum mechanics?.- Interaction = exchange of quanta.- Proof of Wigner's theorem. 2nd edition new topics: A very brief history of Matrix mechanics.- Hydrogen atom and O(4).- Minimum Uncertainty States.- Time Energy Uncertainty Relations?.- Force = curvature in Quantum Mechanics too!.- What is an ‘essentially self-adjoint’ operator?.- Time re-parametrization in path-integrals.- What are rigged Hilbert spaces?.- Relativistic configuration states, Dirac and Weyl equations.

Pankaj Sharan is a professor retired from the Department of Physics at Jamia Millia Islamia, New Delhi. His research interests are chiefly in quantum mechanics, quantum field theory and general relativity. Over a teaching career spanning four decades, he has taught courses on quantum mechanics, quantum field theory, classical mechanics, general relativity and mathematical physics. He is the author of the book Spacetime, Geometry and Gravitation (Birkhäuser, 2009).

• 1st edition: Position operators of non-relativistic quantum mechanics.- A bundle picture of quantum mechanics.- A beam of particles = a plane wave?.- Star-product formulation of quantum mechanics.- Can there be a non-linear quantum mechanics?.- Interaction = exchange of quanta.- Proof of Wigner's theorem. 2nd edition new topics: A very brief history of Matrix mechanics.- Hydrogen atom and O(4).- Minimum Uncertainty States.- Time Energy Uncertainty Relations?.- Force = curvature in Quantum Mechanics too!.- What is an ‘essentially self-adjoint’ operator?.- Time re-parametrization in path-integrals.- What are rigged Hilbert spaces?.- Relativistic configuration states, Dirac and Weyl equations.