This book covers both the pre-quantum and post-quantum development of theoretical physics in a straightforward but fairly rigorous style. Unlike most modern physics courses which gloss over the basic physic subjects in preference to specialised topics like solid state physics, electronics, plasma physics, nanotechnology, cosmology, astrophysics and computer science, this book brings together the various branches of theoretical physics on one platform to give a panoramic view of the subject. The first four chapters of the book deal with the classical topics of Hamiltonian mechanics, theories of relativity, electromagnetic theory of radiation and thermodynamics. They are followed by chapters on atomic spectra and quantum mechanics, spectra of diatomic molecules, quantum theory of radiation, statistical mechanics, and nuclear and particle physics. Guided exercises form a unique feature of this book.

The broad coverage of topics in theoretical physics makes this book an invaluable reference for senior undergraduate and postgraduate students of all branches of physics as well as research workers and physics teachers. The book will also serve for a foundation course for allied subjects such as astrophysics, geophysics, meteorology, laser physics and plasma physics.

Table of Content
Chapter 1. Hamiltonian Mechanics Introduction; System of n particles in Cartesian coordinates; Generalised quantities; Validity of Lagrangian and Hamiltonian equations in generalized coordinates; Principle of least action; Poisson brackets; Contact transformation; Hamilton-Jacobi equation; Some applications of Hamilton-Jacobi equations; The two-body problem; Virial theorem; Problems Chapter 2. Special and General Theories of Relativity Background; Lorentz transformations; Generalised Lorentz transformations; Kinematic applications; Minkowski space; Relativistic mechanics; Elements of general theory of relativity; Gravitational lensing; Problems Chapter 3. Classical Theory of Radiation Maxwell’s equations; Electromagnetic waves; Electromagnetic radiation by a molecule; Harmonic oscillator; Properties of transmitting medium; Relativistic transformation of electromagnetic fields; Electrodynamics of moving charges; Scattering of small particles; Appendix; Problems Chapter 4. Thermodynamics Definitions; Equation of state; Changes in thermodynamic systems; First law of thermodynamics; Specific heats; Second law of thermodynamics; Absolute temperature; Entropy; The phase rule; Important thermodynamic functions; Theorem of radiation; Spectrum of thermal radiation; Problems Chapter 5. Atomic Spectra and Quantum Mechanics Bohr’s theory of hydrogen atom; Sommerfeld’s modification of Bohr’s theory; Fundamentals of quantum mechanics; One-dimensional motion; Hydrogen and hydrogen-like atoms in quantum mechanics; Electron spin; Effect of spin in other atoms; Zeeman and Stark effects; Problems Chapter 6. Molecular Spectra Introduction; Pure rotational bands; Vibration-rotation bands; Electronic bands; Multiplet structure of electronic states; Isotope effects; Strengths of bands and lines; Some typical examples of molecular spectra; Problems Chapter 7. Quantum Theory of Radiation Quantization of pure radiation; Radiation and matter; First order approximation for transition; Computation of transition probabilities; Absorption, emission, and Einstein coefficients; Weisskopf.-Wigner picture; Problems Chapter 8. Statistical Mechanics Kinetic theory of gases; Fundamentals of statistical mechanics; Expression for probability; Population functions; Equation of state for fermions; Some aspects of Bose gas; Classical non-degenerate state; Departure from thermodynamic equilibrium; Problems Chapter 9. Elements of Nuclear and Particle Physics Discovery of the nucleus; Structure of the nucleus; Nuclear reactions and liquid-drop model of nucleus; Elements of particle physics; Applications in astrophysics; Problems Bibliography Index