Superconformal algebra
{{Short description|Algebra combining both supersymmetry and conformal symmetry}}
{{cleanup|date=May 2015|reason=This stub is remarkably poorly written and should be fixed to read in a more pedagogical fashion}}
In theoretical physics, the superconformal algebra is a graded Lie algebra or superalgebra that combines the conformal algebra and supersymmetry. In two dimensions, the superconformal algebra is infinite-dimensional. In higher dimensions, superconformal algebras are finite-dimensional and generate the superconformal group (in two Euclidean dimensions, the Lie superalgebra does not generate any Lie supergroup).
Superconformal algebra in dimension greater than 2
The conformal group of the -dimensional space is and its Lie algebra is . The superconformal algebra is a Lie superalgebra containing the bosonic factor and whose odd generators transform in spinor representations of . Given Kac's classification of finite-dimensional simple Lie superalgebras, this can only happen for small values of and . A (possibly incomplete) list is
- in 3+0D thanks to ;
- in 2+1D thanks to ;
- in 4+0D thanks to ;
- in 3+1D thanks to ;
- in 2+2D thanks to ;
- real forms of in five dimensions
- in 5+1D, thanks to the fact that spinor and fundamental representations of are mapped to each other by outer automorphisms.
Superconformal algebra in 3+1D
According to {{cite book |doi=10.1007/0-306-47056-X_17|chapter=Introduction to Rigid Supersymmetric Theories |title=Confinement, Duality, and Non-Perturbative Aspects of QCD |series=NATO Science Series: B |year=2002 |last1=West |first1=P. C. |volume=368 |pages=453–476 |arxiv=hep-th/9805055 |isbn=0-306-45826-8 |s2cid=119413468 }}
{{cite journal
| last = Gates | first = S. J.
| last2 = Grisaru | first2 = Marcus T.
| last3 = Rocek | first3 = M.
| author3-link = Martin Rocek
| last4 = Siegel | first4 = W.
| author4-link = Warren Siegel
| year = 1983
| title = Superspace, or one thousand and one lessons in supersymmetry
| journal = Frontiers in Physics
| volume = 58 | pages = 1–548
| arxiv = hep-th/0108200
| bibcode = 2001hep.th....8200G
| doi =
}} the superconformal algebra with supersymmetries in 3+1 dimensions is given by the bosonic generators , , , , the U(1) R-symmetry , the SU(N) R-symmetry and the fermionic generators , , and . Here, denote spacetime indices; left-handed Weyl spinor indices; right-handed Weyl spinor indices; and the internal R-symmetry indices.
The Lie superbrackets of the bosonic conformal algebra are given by
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where η is the Minkowski metric; while the ones for the fermionic generators are:
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The bosonic conformal generators do not carry any R-charges, as they commute with the R-symmetry generators:
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But the fermionic generators do carry R-charge:
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Under bosonic conformal transformations, the fermionic generators transform as:
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Superconformal algebra in 2D
{{main|super Virasoro algebra}}
There are two possible algebras with minimal supersymmetry in two dimensions; a Neveu–Schwarz algebra and a Ramond algebra. Additional supersymmetry is possible, for instance the N = 2 superconformal algebra.
See also
References
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{{Supersymmetry topics}}
{{String theory topics |state=collapsed}}
{{DEFAULTSORT:Superconformal Algebra}}
Category:Conformal field theory
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