theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experim ...

, extended supersymmetry is supersymmetry whose infinitesimal generators

Q_i^\alpha

carry not only a

spinor In geometry and physics, spinors are elements of a complex vector space that can be associated with Euclidean space. Like geometric vectors and more general tensors, spinors transform linearly when the Euclidean space is subjected to a sligh ...

index

\alpha

, but also an additional index

i=1,2 \dots \mathcal

where

\mathcal

is integer (such as 2 or 4). Extended supersymmetry is also called

\mathcal=2

\mathcal=4

supersymmetry, for example. Extended supersymmetry is very important for analysis of mathematical properties of quantum field theory and

superstring theory Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. 'Superstring theory' is a shorthand for supersymmetric string t ...

. The more extended supersymmetry is, the more it constrains physical observables and parameters.

See also