approximate theory
1approximate theory — artutinė teorija statusas T sritis fizika atitikmenys: angl. approximate theory vok. Näherungstheorie, f rus. приближённая теория, f pranc. théorie approximative, f …
2Approximate identity — In functional analysis, a right approximate identity in a Banach algebra, A , is a net (or a sequence) :{,e lambda : lambda in Lambda,}such that for every element, a , of A , the net (or sequence):{,ae lambda:lambda in Lambda,}has limit a… …
3Effective field theory — In physics, an effective field theory is an approximate theory (usually a quantum field theory) that includes appropriate degrees of freedom to describe physical phenomena occurring at a chosen length scale, while ignoring substructure and… …
4Density functional theory — Electronic structure methods Tight binding Nearly free electron model Hartree–Fock method Modern valence bond Generalized valence bond Møller–Plesset perturbation theory …
5probability theory — Math., Statistics. the theory of analyzing and making statements concerning the probability of the occurrence of uncertain events. Cf. probability (def. 4). [1830 40] * * * Branch of mathematics that deals with analysis of random events.… …
6Perturbation theory — This article describes perturbation theory as a general mathematical method. For perturbation theory as applied to quantum mechanics, see perturbation theory (quantum mechanics). Perturbation theory comprises mathematical methods that are used to …
7Perturbation theory (quantum mechanics) — In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a …
8Particle physics and representation theory — There is a natural connection, first discovered by Eugene Wigner, between the properties of particles, the representation theory of Lie groups and Lie algebras, and the symmetries of the universe. According to it, the different states of an… …
9Molecular orbital theory — In chemistry, molecular orbital (MO) theory is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole… …
10Old quantum theory — Quantum mechanics Uncertainty principle …
