nLab adinkra

Contents

Context

Superalgebra

Representation theory

Contents

Idea

In super-representation theory, what is called adinkras (Faux-Gates 04) is a graphical tool for denoting those representations (super multiplets) of the 𝒩\mathcal{N}-extended supersymmetry algebras in one dimension (supersymmetric quantum mechanics with N supersymmetries) for which the supersymmetry generators act, up to derivatives and prefactors, by permutation of superfield components. These are called adinkraic representations (Zhang 13, p. 16).

While adinkraic representations are special among all representations of the 1-dimensional 𝒩\mathcal{N}-extended supersymmetry algebra, the idea is that the dimensional reduction of representations (supermultiplets) of higher dimensional supersymmetry algebras down to 1d are of this form, at least for dimensional reduction from d=4d = 4 and N=4N = \mathbf{4} (GGMPPRW 09, section 3, Gates-Hubsch-Stiffler 14).

The classification of adinkras, and hence of adinkraic representations, turns out to be controlled by linear codes (Doran & Faux & Gates & HubschIgaLandweberMiller 11) and to be related to certain special super Riemann surfaces via dessins d'enfants (Doran & Iga & Landweber & Mendez-Diez 13, Doran & Iga & Kostiuk &Mendes-Diez 16).

Definition

For background, see at geometry of physics – supersymmetry.

For NN \in \mathbb{N}, write 1|N\mathbb{R}^{1 \vert N} for the super Lie algebra over the real numbers that is spanned by a single generator PP in even (i.e., bosonic) degree and NN generators Q IQ_I, I{1,2,,N}I \in \{1, 2, \cdots, N\} in odd (i.e., fermionic) degree, whose only non-trivial components of the super-Lie bracket are

[Q I,Q J]=2δ IJP={2P | I=J 0 | otherwise [Q_I, Q_J] = 2 \delta_{I J} P = \left\{ \array{ 2 P & \vert & I = J \\ 0 & \vert & \text{otherwise} } \right.

This is the 1-dimensional NN-extended super translation super Lie algebra. We may think of this as the super-translational symmetry of 1-dimensional NN-extended super Minkowski spacetime.

Consider then super Lie algebra representations of 1|N\mathbb{R}^{1 \vert N} on super vector spaces of smooth superfields on 1|N\mathbb{R}^{1 \vert N} (regarded as a supermanifold) and such that the bosonic generator PP acts as the derivative operator on smooth functions on 1\mathbb{R}^1 in each component. If in addition the representation is such that in the canonical linear basis the odd generators Q IQ_I send even/odd basis elements ϕ i\phi_i to single odd/even basis elements ψ j\psi_j (as opposed to linear combinations of them), hence if the Q IQ_I act apart from degree-shift and possibly differentiation by permutations on the components of the superfields, then this representation of 1|N\mathbb{R}^{1\vert N} is called adinkraic. (Zhang 13, p. 16).

The corresponding adinkra is the bipartite graph which expresses these permutations:

table grabbed from Doran & Iga & Landweber & Mendez-Diez 13, p. 7

graphics grabbed from Iga-Zhang 15, p. 3

Classification

The topology of an adinkra graph together with its edge coloring in {1,2,,N}\{1,2, \cdots, N\} is called its chromotopology.

The set of adinkra chromotopologies is equivalent to the set of colored NN-cubs modulo doubly even length-NN linear codes (Doran-Faux-Gates-Hubsch-Iga-Landweber-Miller 11)

(A linear code of length NN is a linear subspace of (𝔽 2) N(\mathbb{F}_2)^N for 𝔽 2\mathbb{F}_2 the prime field with two elements and it is doubly even if every element has weight a multiple of 4. )

see Zhang 13, chapter 2

graphics grabbed from Iga-Zhang 15, p. 4

From supermultiplets in higher dimensions

The dimensional reduction of the smallest supermultiplets of d=4,N=4d = 4, N = \mathbf{4} supersymmetry down to 1d yield adinkraic representations (GGMPPRW 09, section 3, Gates-Hubsch-Stiffler 14).

Corresponding adinkras for the chiral scalar supermultiplet (CM), the vector multiplet (VM) and the tensor multiplet (TM) look as follows:

References

For an introduction to adinkras, see the talk

The concept of adinkras was introduced into supersymmetry representation theory in

and further developed in the article

and many more (“DFGHIL collaboration”). For instance the relation to Clifford supermodules is discussed in

kinetic terms are discussed in

The classification of adinkras in terms of graphs and linear codes is due to

and discussed in mathematical detail in

The dimensional reduction of the standard supermultiplets of D=4,𝒩=1D = 4, \mathcal{N} = 1 supersymmetry to adinkraic representations of D=1,𝒩=4D = 1, \mathcal{N}=4 is due to

See also

Discussion for D=11D=11, 𝒩=1\mathcal{N}=1:

  • Jim Gates, Yangrui Hu, S.-N. Hazel Mak, Adinkra Foundation of Component Decomposition and the Scan for Superconformal Multiplets in 11D, 𝒩=1\mathcal{N} = 1 Superspace (arXiv:2002.08502)

The relation of adinkras to special super Riemann surfaces via dessins d'enfants is due to

Further developments includes

  • Mathew Calkins, D. E. A. Gates, Jim Gates Jr., Kory Stiffler, Adinkras, 0-branes, Holoraumy and the SUSY QFT/QM Correspondence (arXiv:1501.00101)

Discussion in the context of spectral triples is in

See also

  • Wes Caldwell, Alejandro Diaz, Isaac Friend, Jim Gates, Jr., Siddhartha Harmalkar, Tamar Lambert-Brown, Daniel Lay, Karina Martirosova, Victor Meszaros, Mayowa Omokanwaye, Shaina Rudman, Daniel Shin, Anthony Vershov, On the Four Dimensional Holoraumy of the 4D4D, 𝒩=1\mathcal{N} = 1 Complex Linear Supermultiplet (arXiv:1702.05453)

  • Kevin Iga, Adinkras: Graphs of Clifford Algebra Representations, Supersymmetry, and Codes (arXiv:2110.01665)

  • Wikipedia, Adinkra symbols (physics)

Last revised on October 6, 2021 at 12:13:15. See the history of this page for a list of all contributions to it.