scalar density
31Dark energy — Not to be confused with dark matter, dark fluid, or dark flow. Physical cosmology …
32Dirac equation — Quantum field theory (Feynman diagram) …
33Divergence — For other uses, see Divergence (disambiguation). Topics in Calculus Fundamental theorem Limits of functions Continuity Mean value theorem Differential calculus  Derivative Change of variables Implicit differentiation …
34Theoretical motivation for general relativity — A Theoretical motivation for general relativity, including the motivation for the geodesic equation and the Einstein field equation, can be obtained from special relativity by examining the dynamics of particles in circular orbits about the earth …
35Feynman 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… …
36Tensor — For other uses, see Tensor (disambiguation). Note that in common usage, the term tensor is also used to refer to a tensor field. Stress, a second order tensor. The tensor s components, in a three dimensional Cartesian coordinate system, form the… …
37Mathematical descriptions of the electromagnetic field — There are various mathematical descriptions of the electromagnetic field that are used in the study of electromagnetism, one of the four fundamental forces of nature. In this article four approaches are discussed. Contents 1 Vector field approach …
38Quantum decoherence — Quantum mechanics Uncertainty principle …
39Wave equation — Not to be confused with Wave function. The wave equation is an important second order linear partial differential equation for the description of waves – as they occur in physics – such as sound waves, light waves and water waves. It arises in… …
40Primordial fluctuations — are density variations in the early universe which are considered the seeds of all structure in the universe. Currently, the most widely accepted explanation for their origin is in the context of cosmic inflation. According to the inflationary… …
