relativistically covariant quantity
1Dirac equation — Quantum field theory (Feynman diagram) …
2Scalar field theory — In theoretical physics, scalar field theory can refer to a classical or quantum theory of scalar fields. A field which is invariant under any Lorentz transformation is called a scalar , in contrast to a vector or tensor field. The quanta of the… …
3Feynman diagram — The Wick s expansion of the integrand gives (among others) the following termNarpsi(x)gamma^mupsi(x)arpsi(x )gamma^ upsi(x )underline{A mu(x)A u(x )};,whereunderline{A mu(x)A u(x )}=int{d^4pover(2pi)^4}{ig {mu u}over k^2+i0}e^{ k(x x )}is the… …
4Path integral formulation — This article is about a formulation of quantum mechanics. For integrals along a path, also known as line or contour integrals, see line integral. The path integral formulation of quantum mechanics is a description of quantum theory which… …
5Mass in general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts …
6General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
7Noether's theorem — This article discusses Emmy Noether s first theorem, which derives conserved quantities from symmetries. For her related theorem on infinite dimensional Lie algebras and differential equations, see Noether s second theorem. For her unrelated… …
8Introduction to special relativity — In physics, special relativity is a fundamental theory about space and time, developed by Albert Einstein in 1905 [ On the Electrodynamics of Moving Bodies . (fourmilab.ch web site): [http://www.fourmilab.ch/etexts/einstein/specrel/www/… …
9Propagator — This article is about Quantum field theory. For plant propagation, see Plant propagation. Quantum field theory …