Field theory of a point particle confined to move on a fixed manifold
In physics, a sigma model is a field theory that describes the field as a point particle confined to move on a fixed manifold. This manifold can be taken to be any Riemannian manifold, although it is most commonly taken to be either a Lie group or a symmetric space. The model may or may not be quantized. An example of the non-quantized version is the Skyrme model; it cannot be quantized due to non-linearities of power greater than 4. In general, sigma models admit (classical) topological soliton solutions, for example, the skyrmion for the Skyrme model. When the sigma field is coupled to a gauge field, the resulting model is described by Ginzburg–Landau theory. This article is primarily devoted to the classical field theory of the sigma model; the corresponding quantized theory is presented in the article titled "non-linear sigma model".
In physics, a sigmamodel is a field theory that describes the field as a point particle confined to move on a fixed manifold. This manifold can be taken...
related to the prototypical Ising model, where at each site of a lattice, a spin σ i ∈ { ± 1 } {\displaystyle \sigma _{i}\in \{\pm 1\}} represents a microscopic...
Sigma (/ˈsɪɡmə/ SIG-mə; uppercase Σ, lowercase σ, lowercase in word-final position ς; Greek: σίγμα) is the eighteenth letter of the Greek alphabet. In...
Wikimedia Commons has media related to Mitsubishi Sigma. Mitsubishi Sigma is a model name that was used by the Japanese automobile manufacturer Mitsubishi...
field configuration of a certain class of non-linear sigmamodels. It was originally proposed as a model of the nucleon by (and named after) Tony Skyrme in...
base model, badged Sigma Galant. The Saturn engine was good for 56 kW (75 hp) of power and 117 N⋅m (86 lb⋅ft) of torque. The mid-range model, the Sigma GL...
Scalar, spinor and gauge Standard Model Chiral model Non-linear sigmamodel Wess–Zumino–Witten model Wess–Zumino model Supersymmetric Yang–Mills Seiberg–Witten...
Six Sigma (6σ) is a set of techniques and tools for process improvement. It was introduced by American engineer Bill Smith while working at Motorola in...
is a nonlinear sigmamodel with the principal homogeneous space of a Lie group G {\displaystyle G} as its target manifold. When the model was originally...
dr_{t}=a(b-r_{t})\,dt+\sigma \,dW_{t}} where Wt is a Wiener process under the risk neutral framework modelling the random market risk factor, in that it models the continuous...
contains exactly one sigma factor subunit, which in the model bacterium Escherichia coli is one of those listed below. The number of sigma factors varies between...
United States in 1986. Six Sigma was developed within Motorola to compete with the kaizen (or lean manufacturing) business model in Japan.[citation needed]...
two-dimensional surfaces. A quantum field theory known as the N = (1,1) sigmamodel is defined on each surface. This theory consist of maps from the surface...
through 1983. The first Sigmas were typically dreadnought acoustic, although Grand Concert Series (GCS) and classical models were also produced from the...
"Eterna Σ" (Sigma) in Japan, "Sapporo" in Europe, and in the US as "Galant Σ" (1988 model year) followed by plain "Sigma" (1989 to 1990 model years). The...
parameter σ {\displaystyle \sigma } . SABR is a dynamic model in which both F {\displaystyle F} and σ {\displaystyle \sigma } are represented by stochastic...
Design for Six Sigma (DFSS) is a collection of best-practices for the development of new products and processes. It is sometimes deployed as an engineering...
the model mean, and { ϵ t } {\displaystyle \{\epsilon _{t}\}} is a white-noise process with zero mean and constant variance σ {\displaystyle \sigma } ...
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