invariant object
81Symmetry group — Not to be confused with Symmetric group. This article is about the abstract algebraic structures. For other meanings, see Symmetry group (disambiguation). A tetrahedron can be placed in 12 distinct positions by rotation alone. These are… …
82Kinematics — Classical mechanics Newton s Second Law History of classical mechanics  …
83Four-momentum — In special relativity, four momentum is the generalization of the classical three dimensional momentum to four dimensional spacetime. Momentum is a vector in three dimensions; similarly four momentum is a four vector in spacetime. The… …
84Scale invariance — In physics and mathematics, scale invariance is a feature of objects or laws that do not change if length scales (or energy scales) are multiplied by a common factor. The technical term for this transformation is a dilatation (also known as… …
85Point spread function — The point spread function (PSF) describes the response of an imaging system to a point source or point object. A related but more general term for the PSF is a system s impulse response. The PSF in many contexts can be thought of as the extended… …
86Postulates of special relativity — See also: Special relativity Postulates of special relativity 1. First postulate (principle of relativity): The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or …
87topology — topologic /top euh loj ik/, topological, adj. topologically, adv. topologist, n. /teuh pol euh jee/, n., pl. topologies for 3. Math. 1. the study of those properties of geometric forms that remain invariant under c …
88Feynman 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… …
89Inversion transformation — Inversion transformations are a natural extension of Poincaré transformations to include all conformal one to one transformations on coordinate space time. They are less studied in physics because unlike the rotations and translations of Poincaré …
90List of important publications in computer science — This is a list of important publications in computer science, organized by field. Some reasons why a particular publication might be regarded as important: Topic creator – A publication that created a new topic Breakthrough – A publication that… …
