Einstein’s General Relativity

Derivations, Applications and Reflections – by Albert Prins

Appendices

Appendix 1

Formulas of General Relativity

Summary of important metric, curvature, and field equations

\( ds^2 = g_{\mu\nu} dx^\mu dx^\nu \)

\( G_{\mu\nu} = \frac{8\pi G}{c^4} T_{\mu\nu} \)

Appendix 2

Derivation of the Derivative of the Christoffel Symbols

Schematic derivation of \( \nabla_\lambda \Gamma^\rho_{\mu\nu} \) and related identities

Appendix 3

Mathematical Derivation of Schwarzschild

Step-by-step: from metric to Riemann and Ricci tensors for the Schwarzschild solution

Appendix 4

The Schwarzschild Formula Extended for Electric Charges

Connection between surface integral and volume source: divergence theorem in curved space

Appendix 5

Schwarzschild Solution Inside a Mass

\( \nabla^2 \Phi = 4\pi G \rho \) as the Newtonian limit of the field equations

Appendix 6

Derivation of Gauss’s Theorem

Relation between flux through a surface and volume

\(\oint_{\partial V} \vec{F}\cdot d\vec{A}=\iiint_V (\vec{\nabla}\cdot\vec{F})\, dV\)

Appendix 7

Derivation of the Laplace and Poisson Equations

\( \nabla^2 \Phi = 4\pi G \rho \) as the Newtonian limit of the field equations

Appendix 8

Tidal Forces

Spaghettification

Appendix 9

Special Relativity

Lorentz transformations, time dilation, length contraction, and \( E = mc^2 \)

Appendix 10

Specific Angular Momentum

Conservation of \(L/m\) in a central potential and in Schwarzschild geometry

Appendix 11

Considerations on Rotation

Rotations

Appendix 12

Derivation of the Euler–Lagrange Equation

Variational principle: \( \frac{d}{d\tau} \left( \frac{\partial L}{\partial \dot{x}^\mu} \right) = \frac{\partial L}{\partial x^\mu} \)