calculus - How to derive a Lorentz covariant, generic solution for

Below, I am reading through how to quantise a complex scalar field, beginning with an example of the Klein-Gordon field. After arriving to the generic solution to the system corresponding to equat

differential geometry - Calculation of a covariant derivative and exterior derivative - Mathematics Stack Exchange

Chapter 3 Relativistic Wave Mechanics

Chapter 2: Lagrangian Mechanics

Schematic representation, for a change of variables x↦u(x), of how the

Maxwell's equations - Wikipedia

A Derivation of The Lorentz Transformation, PDF, Spacetime

Introduction to Tensor Calculus, Relativity and Cosmology: Lawden, D. F.: 9780486425405: Books

Exact Riemann solver for non-convex relativistic hydrodynamics, Journal of Fluid Mechanics

Solved 1.2. Given an infinitesimal Lorentz transformation