The Segre classification is an algebraic classification of rank two
symmetric tensor
In mathematics, a symmetric tensor is an unmixed tensor that is invariant under a permutation of its vector arguments:
:T(v_1,v_2,\ldots,v_r) = T(v_,v_,\ldots,v_)
for every permutation ''σ'' of the symbols Alternatively, a symmetric tens ...
s. It was proposed by the italian mathematician
Corrado Segre
Corrado Segre (20 August 1863 – 18 May 1924) was an Italian mathematician who is remembered today as a major contributor to the early development of algebraic geometry.
Early life
Corrado's parents were Abramo Segre and Estella De Ben ...
in 1884.
The resulting types are then known as Segre types. It is most commonly applied to the
energy–momentum tensor Energy–momentum may refer to:
* Four-momentum
* Stress–energy tensor
* Energy–momentum relation
{{dab ...
(or the
Ricci tensor
In differential geometry, the Ricci curvature tensor, named after Gregorio Ricci-Curbastro, is a geometric object which is determined by a choice of Riemannian or pseudo-Riemannian metric on a manifold. It can be considered, broadly, as a measure ...
) and primarily finds application in the classification of
exact solutions in general relativity
In general relativity, an exact solution is a (typically closed form) solution of the Einstein field equations whose derivation does not invoke simplifying approximations of the equations, though the starting point for that derivation may be a ...
.
See also
*
Corrado Segre
Corrado Segre (20 August 1863 – 18 May 1924) was an Italian mathematician who is remembered today as a major contributor to the early development of algebraic geometry.
Early life
Corrado's parents were Abramo Segre and Estella De Ben ...
*
Jordan normal form
\begin
\lambda_1 1\hphantom\hphantom\\
\hphantom\lambda_1 1\hphantom\\
\hphantom\lambda_1\hphantom\\
\hphantom\lambda_2 1\hphantom\hphantom\\
\hphantom\hphantom\lambda_2\hphantom\\
\hphantom\lambda_3\hphantom\\
\hphantom\ddots\hphantom\\
...
*
Petrov classification
References
* See ''section 5.1'' for the Segre classification.
*
Linear algebra
Tensors
Tensors in general relativity
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