S. Rajasekar received his B.Sc. and M.Sc. in Physics both from St. Joseph’s College, Tiruchirapalli. He was awarded his Ph.D. degree from Bharathidasan University in 1992 under the supervision of Prof. M. Lakshmanan. In 1993, he joined as a Lecturer at the Department of Physics, Manonmaniam Sundaranar University, Tirunelveli. In 2003, the book Nonlinear Dynamics: Integrability, Chaos and Patterns written by Prof. M. Lakshmanan and the author was published by Springer. In 2005, he joined as a Professor at the School of Physics, Bharathidasan University. In 2016 Springer published Nonlinear Resonances written by Prof. Miguel A.F. Sanjuan and the author. In 2021 Professors U.E. Vincent, P.V.E. McClintock, I.A. Khovanov and the author compiled and edited two issues of Philosophical Transactions of the Royal Society A on the theme Vibrational and Stochastic Resonances in Driven Nonlinear Systems. He has also edited Recent Trends in Chaotic, Nonlinear and Complex Dynamics with Professors Jan Awrejecewicz and Minvydas Ragulskis, published by World Scientific in 2022. His recent research focuses on nonlinear dynamics with a special emphasize on nonlinear resonances. He has authored or co-authored more than 120 research papers in nonlinear dynamics.R. Velusamy received his B.Sc. degree in Physics from the Ayya Nadar Janaki Ammal College, Sivakasi in 1972 and M.Sc. in Physics from the P.S.G. Arts and Science College, Coimbatore in 1974. He worked as a demonstrator in the Department of Physics in P.S.G. Arts and Science College during 1974-77. He received an M.S. Degree in Electrical Engineering at Indian Institute of Technology, Chennai in the year 1981. In the same year, he joined in the Ayya Nadar Janaki Ammal College as an Assistant Professor in Physics. He was awarded a M.Phil. degree in Physics in the year 1988. He retired in the year 2010. His research topics are quantum confined systems and wave packet dynamics.

• 1. Why Was Quantum Mechanics Developed? 2. Schrödinger Equation and Wave Function. 3. Operators, Eigenvalues and Eigenfunctions. 4. Exactly Solvable Systems I: Bound States. 5. Exactly Solvable Systems II: Scattering States. 6. Matrix Mechanics. 7. Various Pictures in Quantum Mechanics and Density Matrix. 8. Heisenberg Uncertainty Principle. 9. Momentum Representation. 10. Wave Packet. 11. Theory of Angular Momentum. 12. Hydrogen Atom. 13. Approximation Methods I: Time-Independent Perturbation Theory. 14. Approximation Methods II: Time-Dependent Perturbation Theory. 15. Approximation Methods III: WKB and Asymptotic Methods. 16. Approximation Methods IV: Variational Method. 17. Scattering Theory. 18. Identical Particles. 19. Relativistic Quantum Theory. 20. Mysteries in Quantum Mechanics. 21. Delayed-Choice Experiments. 22. Fractional Quantum Mechanics. 23. Numerical Methods for Quantum Mechanics. Appendices. Index.

S. Rajasekar received his B.Sc. and M.Sc. in Physics both from St. Joseph’s College, Tiruchirapalli. He was awarded his Ph.D. degree from Bharathidasan University in 1992 under the supervision of Prof. M. Lakshmanan. In 1993, he joined as a Lecturer at the Department of Physics, Manonmaniam Sundaranar University, Tirunelveli. In 2003, the book Nonlinear Dynamics: Integrability, Chaos and Patterns written by Prof. M. Lakshmanan and the author was published by Springer. In 2005, he joined as a Professor at the School of Physics, Bharathidasan University. In 2016 Springer published Nonlinear Resonances written by Prof. Miguel A.F. Sanjuan and the author. In 2021 Professors U.E. Vincent, P.V.E. McClintock, I.A. Khovanov and the author compiled and edited two issues of Philosophical Transactions of the Royal Society A on the theme Vibrational and Stochastic Resonances in Driven Nonlinear Systems. He has also edited Recent Trends in Chaotic, Nonlinear and Complex Dynamics with Professors Jan Awrejecewicz and Minvydas Ragulskis, published by World Scientific in 2022. His recent research focuses on nonlinear dynamics with a special emphasize on nonlinear resonances. He has authored or co-authored more than 120 research papers in nonlinear dynamics.R. Velusamy received his B.Sc. degree in Physics from the Ayya Nadar Janaki Ammal College, Sivakasi in 1972 and M.Sc. in Physics from the P.S.G. Arts and Science College, Coimbatore in 1974. He worked as a demonstrator in the Department of Physics in P.S.G. Arts and Science College during 1974-77. He received an M.S. Degree in Electrical Engineering at Indian Institute of Technology, Chennai in the year 1981. In the same year, he joined in the Ayya Nadar Janaki Ammal College as an Assistant Professor in Physics. He was awarded a M.Phil. degree in Physics in the year 1988. He retired in the year 2010. His research topics are quantum confined systems and wave packet dynamics.

• 1. Why Was Quantum Mechanics Developed? 2. Schrödinger Equation and Wave Function. 3. Operators, Eigenvalues and Eigenfunctions. 4. Exactly Solvable Systems I: Bound States. 5. Exactly Solvable Systems II: Scattering States. 6. Matrix Mechanics. 7. Various Pictures in Quantum Mechanics and Density Matrix. 8. Heisenberg Uncertainty Principle. 9. Momentum Representation. 10. Wave Packet. 11. Theory of Angular Momentum. 12. Hydrogen Atom. 13. Approximation Methods I: Time-Independent Perturbation Theory. 14. Approximation Methods II: Time-Dependent Perturbation Theory. 15. Approximation Methods III: WKB and Asymptotic Methods. 16. Approximation Methods IV: Variational Method. 17. Scattering Theory. 18. Identical Particles. 19. Relativistic Quantum Theory. 20. Mysteries in Quantum Mechanics. 21. Delayed-Choice Experiments. 22. Fractional Quantum Mechanics. 23. Numerical Methods for Quantum Mechanics. Appendices. Index.

S. Rajasekar received his B.Sc. and M.Sc. in Physics both from St. Joseph’s College, Tiruchirapalli. He was awarded his Ph.D. degree from Bharathidasan University in 1992 under the supervision of Prof. M. Lakshmanan. In 1993, he joined as a Lecturer at the Department of Physics, Manonmaniam Sundaranar University, Tirunelveli. In 2003, the book Nonlinear Dynamics: Integrability, Chaos and Patterns written by Prof. M. Lakshmanan and the author was published by Springer. In 2005, he joined as a Professor at the School of Physics, Bharathidasan University. In 2016 Springer published Nonlinear Resonances written by Prof. Miguel A.F. Sanjuan and the author. In 2021 Professors U.E. Vincent, P.V.E. McClintock, I.A. Khovanov and the author compiled and edited two issues of Philosophical Transactions of the Royal Society A on the theme Vibrational and Stochastic Resonances in Driven Nonlinear Systems. He has also edited Recent Trends in Chaotic, Nonlinear and Complex Dynamics with Professors Jan Awrejecewicz and Minvydas Ragulskis, published by World Scientific in 2022. His recent research focuses on nonlinear dynamics with a special emphasize on nonlinear resonances. He has authored or co-authored more than 120 research papers in nonlinear dynamics.R. Velusamy received his B.Sc. degree in Physics from the Ayya Nadar Janaki Ammal College, Sivakasi in 1972 and M.Sc. in Physics from the P.S.G. Arts and Science College, Coimbatore in 1974. He worked as a demonstrator in the Department of Physics in P.S.G. Arts and Science College during 1974-77. He received an M.S. Degree in Electrical Engineering at Indian Institute of Technology, Chennai in the year 1981. In the same year, he joined in the Ayya Nadar Janaki Ammal College as an Assistant Professor in Physics. He was awarded a M.Phil. degree in Physics in the year 1988. He retired in the year 2010. His research topics are quantum confined systems and wave packet dynamics.

• 1. Why Was Quantum Mechanics Developed? 2. Schrödinger Equation and Wave Function. 3. Operators, Eigenvalues and Eigenfunctions. 4. Exactly Solvable Systems I: Bound States. 5. Exactly Solvable Systems II: Scattering States. 6. Matrix Mechanics. 7. Various Pictures in Quantum Mechanics and Density Matrix. 8. Heisenberg Uncertainty Principle. 9. Momentum Representation. 10. Wave Packet. 11. Theory of Angular Momentum. 12. Hydrogen Atom. 13. Approximation Methods I: Time-Independent Perturbation Theory. 14. Approximation Methods II: Time-Dependent Perturbation Theory. 15. Approximation Methods III: WKB and Asymptotic Methods. 16. Approximation Methods IV: Variational Method. 17. Scattering Theory. 18. Identical Particles. 19. Relativistic Quantum Theory. 20. Mysteries in Quantum Mechanics. 21. Delayed-Choice Experiments. 22. Fractional Quantum Mechanics. 23. Numerical Methods for Quantum Mechanics. Appendices. Index.