nonvanishing vector
13-sphere — Stereographic projection of the hypersphere s parallels (red), meridians (blue) and hypermeridians (green). Because this projection is conformal, the curves intersect each other orthogonally (in the yellow points) as in 4D. All curves are circles …
2Congruence (manifolds) — In the theory of smooth manifolds, a congruence is the set of integral curves defined by a nonvanishing vector field defined on the manifold. Congruences are an important concept in general relativity, and are also important in parts of… …
3Lie group — Lie groups …
4Spacetime — For other uses of this term, see Spacetime (disambiguation). Two dimensional analogy of spacetime distortion. Matter changes the geometry of spacetime, this (curved) geometry being interpreted as gravity. White lines do not represent the… …
5Congruence — is the state achieved by coming together, the state of agreement. The Latin congruō meaning “I meet together, I agree”. As an abstract term, congruence means similarity between objects. Congruence, as opposed to equivalence or approximation, is a …
6Continuous spatial automaton — Continuous spatial automata, unlike cellular automata, have a continuum of locations. The state of a location is a finite number of real numbers. Time is also continuous, and the state evolves according to differential equations. One important… …
7Pp-wave spacetime — In general relativity, the pp wave spacetimes, or pp waves for short, are an important family of exact solutions of Einstein s field equation. These solutions model radiation moving at the speed of light. This radiation may consist of:*… …
8Monochromatic electromagnetic plane wave — In general relativity, the monochromatic electromagnetic plane wave spacetime is the analog of the monochromatic plane waves known from Maxwell s theory. The precise definition of the solution is a bit complicated, but very instructive. Any exact …
9Dirac bracket — The Dirac bracket is a generalization of the Poisson bracket developed by Paul Dirac to correctly treat systems with second class constraints in Hamiltonian mechanics and canonical quantization. It is an important part of Dirac s development of… …
10Continuum mechanics — Continuum mechanics …
