# supersymmetry

###### Definition 0.1.

*Supersymmetry* or Poincaré, (extended) quantum symmetry is usually defined as an extension of ordinary spacetime symmetries obtained by adjoining $N$ spinorial generators $Q$ whose anticommutator yields a
translation generator: $\{Q,Q\}=\left\{P\right\}$.

As further explained in ref. [1]:

“This

(super)symmetry…(of thesuperspace)… can be realized on ordinary fields (that are defined as certain functions of physical spacetime(s)) by transformations that mix bosons and fermions.Such realizations suffice to study supersymmetry (one can write invariant actions, etc.) but are as cumbersome and inconvenient as doing vector calculus component by component. A compact”, which is defined next.^{}alternative to this ‘component field’ approach is given by thesuperspace–superfieldapproach

###### Definition 0.2.

*Quantum superspace, or superspacetimes*, can be defined as an extension(s) of ordinary spacetime(s) to include
additional anticommuting coordinates, for example, in the form of $N$ two-component Weyl spinors $\theta $.

###### Definition 0.3.

*(Quantum) superfields* $\mathrm{\Psi}(x,\theta )$ are *functions* defined over such superspaces, or superspacetimes.
Taylor series^{} expansions of the superfield functions can be then performed with respect to the anticommuting coordinates $\theta $; this Taylor series has only a finite number of terms and the series expansion
coefficients obtained in this manner are the ordinary ‘component fields’ specified above.

Remarks:
Supersymmetry is expected to be manifested, or observable, in such superspaces, that is, the *supersymmetry algebras* are represented by translations and rotations involving *both* the spacetime and the anticommuting coordinates. Then, the transformations of the ‘component fields’ can be computed from the Taylor expansion of
the *translated and rotated superfields*. Especially important are those transformations that mix boson
and fermion symmetries; further details are found in ref. [2].

## References

- 1 J.S. Gates, Jr, et al. “Superspace”., arxiv-hep-th/0108200 preprint (1983).
- 2 “Preprint of 1,001 Lessons in Supersymmetry.” http://arxiv.org/abs/hep-th/0108200on line PDF.

Title | supersymmetry |

Canonical name | Supersymmetry |

Date of creation | 2013-03-22 18:17:00 |

Last modified on | 2013-03-22 18:17:00 |

Owner | bci1 (20947) |

Last modified by | bci1 (20947) |

Numerical id | 22 |

Author | bci1 (20947) |

Entry type | Definition |

Classification | msc 55U40 |

Classification | msc 55-02 |

Classification | msc 81Q60 |

Classification | msc 81R50 |

Classification | msc 81R15 |

Synonym | extended quantum symmetry structures |

Synonym | generalized double algebras |

Synonym | supersymmetries |

Related topic | QuantumAlgebraicTopology |

Related topic | AlgebraicFoundationsOfQuantumAlgebraicTopology |

Related topic | SuperfieldsSuperspace |

Related topic | LieSuperalgebra3 |

Defines | extended quantum symmetry structures |

Defines | both local and global |