Here are some notes on the book W. Greiner: Relativistic Quantum Mechanics (Wave Equations); 3rd Edition, Springer-Verlag (2000). The book contains no exercises for the reader (well, there are exercises, but the solutions are given in detail in the book), so I'm providing only my own notes on the text to summarize the contents and clarify a few points. On the whole, though, Greiner tends to provide detailed derivations of most of the results, so there aren't many steps to fill in.

**Chapter 1: Relativistic Wave Equation for Spin-0 Particles: The Klein-Gordon Equation and its Applications**

- 1.1 Notation for Relativistic Quantum Mechanics
- 1.2 Klein-gordon equation - derivation and continuity equations
- 1.3 Klein-gordon equation - nonrelativistic limit
- 1.4 Klein-gordon equation - charged particles
- 1.5, Ex. 1.3 Energy-momentum tensor for a general Lagrange density
- 1.5, Ex. 1.4 Schrödinger equation: Lagrange density & Energy-momentum tensor
- 1.6 Klein-Gordon equation in Schrödinger form
- 1.8 Klein-Gordon equation in the Feshbach-Villars representation
- 1.8, Ex. 1.7 Klein-Gordon equation in Schrödinger form - Lagrangian, energy-momentum tensor
- 1.8, Ex. 1.8, 1.9 Klein-Gordon equation in Feshbach-Villars form - Operator transformations and solutions
- 1.9 Klein-Gordon equation - interaction with electromagnetic field
- 1.9, Ex. 1.10, 1.11 Klein-Gordon equation with Coulomb potential