q-Deformed Superalgebras

Quadratic relations of the deformed $W$-superalgebra ${\cal W}_{q, t}\bigl(A(M,N)\bigr)$

We find the free field construction of the basic $W$-current and screening currents for the deformed $W$-superalgebra ${\cal W}_{q,t}\bigl(A(M,N)\bigr)$ associated with Lie superalgebra of type $A(M,N)$. Using this free field construction, we introduce the higher $W$-currents and obtain a closed set of quadratic relations among them. These relations are independent of the choice of Dynkin-diagrams for the Lie superalgebra $A(M,N)$, though the screening currents are not. This allows us to define ${\cal W}_{q,t}\bigl(A(M,N)\bigr)$ by generators and relations.

Formulation of Supersymmetry on a Lattice as a Representation of a Deformed Superalgebra

The lattice superalgebra of the link approach is shown to satisfy a Hopf algebraic supersymmetry where the difference operator is introduced as a momentum operator. The breakdown of the Leibniz rule for the lattice difference operator is accommodated as a coproduct operation of (quasi)triangular Hopf algebra and the associated field theory is consistently defined as a braided quantum field theory. Algebraic formulation of path integral is perturbatively defined and Ward-Takahashi identity can be derived on the lattice. The claimed inconsistency of the link approach leading to the ordering ambi…

A decription of the quantum superalgebra $U_q[osp(2n+1/2m)]$ via Green generators

A description of the orthosymplectic Lie superalgebra $osp(2n+1/2m)$ and also of its $q-$deformed analogue $U_q[osp(2n+1/2m)]$ in terms of a new set of generators, called Green generators, is given. These generators are very different form the well known Chevalley generators. Mathematically the Green generators are the root vectors, corresponding to the positive and the negative orthogonal roots. Physically, they consist of $m$ pairs of (deformed) para-Bose operators and $n$ pairs of (deformed) para-Fermi operators.

Killing superalgebra deformations of ten-dimensional supergravity backgrounds

We explore Lie superalgebra deformations of the Killing superalgebras of some ten-dimensional supergravity backgrounds. We prove the rigidity of the Poincare superalgebras in types I, IIA and IIB, as well as of the Killing superalgebra of the Freund-Rubin vacuum of type IIB supergravity. We also prove rigidity of the Killing superalgebras of the NS5, D0, D3, D4 and D5 branes, whereas we exhibit the possible deformations of the D1, D2, D6 and D7 brane Killing superalgebras, as well as of that of the type II fundamental string solutions. We relate the superalgebra deformations of the D2 and D6 b…

AdS3/CFT2 and q-Poincare' superalgebras

We discover that a certain deformation of the 1+1 dimensional Poincare' superalgebra is exactly realised in the massless sector of the AdS3/CFT2 integrable scattering problem. Deformed Poincaré superalgebras were previously noticed to appear in the AdS5/CFT4 correspondence - which displays only massive excitations -, but they were there only a partial symmetry. We obtain a representation of the boost operator and its coproduct, and show that the comultiplication exactly satisfies the homomorphism property. We present a classical limit, and finally speculate on an analogy with the physics of ph…

经典与量子sl（1| 2）超代数、Casimir算子和量子链Hamilton算子

Classical and Quantum sl(1|2) Superalgebras, Casimir Operators and Quantum Chain Hamiltonians

我们研究了双参数变形超代数$U_{qs}(sl(1|2))$，并将其结果用于量子链哈密顿量的构造。这项研究是在框架内的塞尔介绍和$R$ -矩阵计划的Faddeev，Reshetikhin和Takhtajan（FRT）。我们证明了存在无穷多个Casimir算子，在未变形的情况下用整数$p > 1$索引，在变形的情况下用$p \in Z$索引，它们服从二次关系。给出了$SL_{qs}(1|2)$上函数的对偶超代数的构造，并讨论了高阶张量积表示。最后，我们构造了基于Casimir算符的量子链哈密顿算符。在变形的情况下，我们发现两个哈密顿描述变形的$t-J$模型。

Anyonic Realization of the Quantum Affine Lie Superalgebra U_q(A(M,N)^{(1)})

We give a realization of the quantum affine Lie superalgebras U_q(A(M,N))^(1) in terms of anyons defined on a one or two-dimensional lattice, the deformation parameter q being related to the statistical parameter $ν$ of the anyons by q = exp(iπν). The construction uses anyons contructed from usual fermionic oscillators and deformed bosonic oscillators. As a byproduct, realization deformed in any sector of the quantum superalgebras U_q(A(M,N)) is obtained.

Deformed Clifford Cl_q(n|m) and orthosymplectic U_q[osp(2n+1|2m)] superalgebras and their root of unity representations

It is shown that the Clifford superalgebra Cl(n|m) generated by m pairs of Bose operators (odd elements) anticommuting with n pairs of Fermi operators (even elements) can be deformed to Cl_q(n|m) such that the latter is a homomorphic image of the quantum superalgebra U_q[osp(2n+1|2m)]. The Fock space F(n|m) of Cl_q(n|m) is constructed. At q being a root of unity (q=\exp ({iπl/k})) q-bosons (and q-fermions) are operators acting in a finite-dimensional subspace F_{l/k}(n|m) of F(n|m). Each F_{l/k}(n|m) is turned through the above mentioned homomorphism into an irreducible (root of unity) U_q[osp…

Higher Spin Symmetries and Deformed Schrödinger Algebra in Conformal Mechanics

The dynamical symmetries of $1+1$-dimensional Matrix Partial Differential Equations with a Calogero potential (with/without the presence of an extra oscillatorial De Alfaro-Fubini-Furlan, DFF, damping term) are investigated. The first-order invariant differential operators induce several invariant algebras and superalgebras. Besides the $sl(2)\oplus u(1)$ invariance of the Calogero Conformal Mechanics, an $osp(2|2)$ invariant superalgebra, realized by first-order and second-order differential operators, is obtained. The invariant algebras with an infinite tower of generators are given by the u…

Twist Deformations of the Supersymmetric Quantum Mechanics

The N-extended Supersymmetric Quantum Mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its Universal Enveloping Superalgebra. Two constructions are possible. For even N one can identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist-deformed (anti)commutators. The main differences…

Scattering in Mass-Deformed N>=4 Chern-Simons Models

We investigate the scattering matrix in mass-deformed N>=4 Chern-Simons models including as special cases the BLG and ABJM theories of multiple M2 branes. Curiously the structure of this scattering matrix in three spacetime dimensions is equivalent to (a) the two-dimensional worldsheet matrix found in the context of AdS/CFT integrability and (b) the R-matrix of the one-dimensional Hubbard model. The underlying reason is that all three models are based on an extension of the psu(2|2) superalgebra which constrains the matrix completely. We also compute scattering amplitudes in one-loop field the…

量子超代数U $_{q}$ [gl（2/2）]的一维表示I.通用$q$的典型表示

Finite-Dimensional Representations of the Quantum Superalgebra U$_{q}$[gl(2/2)]: I. Typical representations at generic $q$

本文构造了量子李超代数$U_{q}[gl(2/2)]$在一般形变参数$q$下的所有典型有限维表示.在非变形的情况下，得到的有限维$U_{q}[gl(2/2)]$ -模$W^{q}$是不可约的，并且可以分解成有限维不可约$U_{q}[gl(2)\oplus gl(2)]$ -子模$V^{q}_{k}$

Maximally extended sl(2|2), q-deformed d(2,1;epsilon) and 3D kappa-Poincaré

We show that the maximal extension sl(2) times psl(2|2) times C3 of the sl(2|2) superalgebra can be obtained as a contraction limit of the semi-simple superalgebra d(2,1;epsilon) times sl(2). We reproduce earlier results on the corresponding q-deformed Hopf algebra and its universal R-matrix by means of contraction. We make the curious observation that the above algebra is related to kappa-Poincaré symmetry. When dropping the graded part psl(2|2) we find a novel one-parameter deformation of the 3D kappa-Poincaré algebra. Our construction also provides a concise exact expression for its univers…

The Classical Trigonometric r-Matrix for the Quantum-Deformed Hubbard Chain

The one-dimensional Hubbard model is an exceptional integrable spin chain which is apparently based on a deformation of the Yangian for the superalgebra gl(2|2). Here we investigate the quantum-deformation of the Hubbard model in the classical limit. This leads to a novel classical r-matrix of trigonometric kind. We derive the corresponding one-parameter family of Lie bialgebras as a deformation of the affine gl(2|2) Kac-Moody superalgebra. In particular, we discuss the affine extension as well as discrete symmetries, and we scan for simpler limiting cases, such as the rational r-matrix for th…

Deformed Twistors and Higher Spin Conformal (Super-)Algebras in Four Dimensions

Massless conformal scalar field in d=4 corresponds to the minimal unitary representation (minrep) of the conformal group SU(2,2) which admits a one-parameter family of deformations that describe massless fields of arbitrary helicity. The minrep and its deformations were obtained by quantization of the nonlinear realization of SU(2,2) as a quasiconformal group in arXiv:0908.3624. We show that the generators of SU(2,2) for these unitary irreducible representations can be written as bilinears of deformed twistorial oscillators which transform nonlinearly under the Lorentz group and apply them to …

Lorentz Symmetry Breaking in $\mathcal{N} =2$ Superspace

In this paper, we will study the deformation of a three dimensional theory with $\mathcal{N} =2$ supersymmetry. This theory will be deformed by the presence of a constant vector field. This deformation will break the Lorentz symmetry. So, we will analyse this theory using $\mathcal{N} =2$ aether superspace. The $\mathcal{N} =2$ aether superspace will be obtained from a deformation of the usual $\mathcal{N} =2$ superspace. This will be done by deforming the generators of the three dimensional $\mathcal{N} =2$ supersymmetry. After analysing this deformed superalgebra, we will derive an explicit …

N=1/2 Deformations of Chiral Superspaces from New Quantum Poincare and Euclidean Superalgebras

We present a large class of supersymmetric classical r-matrices, describing the supertwist deformations of Poincare and Euclidean superalgebras. We consider in detail new family of four supertwists of N=1 Poincare superalgebra and provide as well their Euclidean counterpart. The proposed supertwists are better adjusted to the description of deformed D=4 Euclidean supersymmetries with independent left-chiral and right-chiral supercharges. They lead to new quantum superspaces, obtained by the superextension of twist deformations of spacetime providing Lie-algebraic noncommutativity of space-time…

Deformed Heisenberg algebra with reflection

A universality of deformed Heisenberg algebra involving the reflection operator is revealed. It is shown that in addition to the well-known infinite-dimensional representations related to parabosons, the algebra has also finite-dimensional representations of the parafermionic nature. We demonstrate that finite-dimensional representations are representations of deformed parafermionic algebra with internal Z_2-grading structure. On the other hand, any finite- or infinite-dimensional representation of the algebra supply us with irreducible representation of osp(1|2) superalgebra. We show that the…

The octonionically-induced ${\cal N}=7$ exceptional $G(3)$ superconformal quantum mechanics

Both the ${\cal N}=7$ superconformal quantum mechanics possessing the exceptional $G(3)$ Lie superalgebra as dynamical symmetry and its associated deformed oscillator with $G(3)$ as spectrum-generating superalgebra are presented. This superconformal quantum mechanics, uniquely defined up to similarity transformations, is obtained via the octonionically-induced "quasi-nonassociative" method employed to derive the exceptional ${\cal N}=8$ $F(4)$ model. To construct the $G(3)$ theories, the covariant embedding of the $7$-dimensional representation of the Lie algebra $g_2$ within the $8\times 8$ m…

Serre presentations of Lie superalgebras

An analogue of Serre's theorem is established for finite dimensional simple Lie superalgebras, which describes presentations in terms of Chevalley generators and Serre type relations relative to all possible choices of Borel subalgebras. The proof of the theorem is conceptually transparent; it also provides an alternative approach to Serre's theorem for ordinary Lie algebras.

Classification of Low Dimensional 3-Lie Superalgebras

A notion of n-Lie algebra introduced by V.T. Filippov can be viewed as a generalization of a concept of binary Lie algebra to the algebras with n-ary multiplication law. A notion of Lie algebra can be extended to Z_2-graded structures giving a notion of Lie superalgebra. Analogously a notion of n-Lie algebra can be extended to Z_2-graded structures by means of a graded Filippov identity giving a notion of n-Lie superalgebra. We propose a classification of low dimensional 3-Lie superalgebras. We show that given an n-Lie superalgebra equipped with a supertrace one can construct the (n+1)-Lie sup…

Killing superalgebras for Lorentzian four-manifolds

We determine the Killing superalgebras underpinning field theories with rigid unextended supersymmetry on Lorentzian four-manifolds by re-interpreting them as filtered deformations of $\mathbb{Z}$-graded subalgebras with maximum odd dimension of the $N{=}1$ Poincaré superalgebra in four dimensions. Part of this calculation involves computing a Spencer cohomology group which, by analogy with a similar result in eleven dimensions, prescribes a notion of Killing spinor, which we identify with the defining condition for bosonic supersymmetric backgrounds of minimal off-shell supergravity in four d…

Applying the q-algebras U'_q(so_n) to quantum gravity: towards q-deformed analog of SO(n) spin networks

Nonstandard q-deformed algebras U'_q(so_n), proposed a decade ago for the needs of representation theory, essentially differ from the standard Drinfeld-Jimbo quantum deformation of the algebras U(so_n) and possess with regard to the latter a number of important advantages. We discuss possible application of the q-algebras U'_q(so_n), within two different contexts of quantum/q-deformed gravity: one concerns q-deforming of D-dimensional (D >= 3) euclidean gravity, the other applies to 2+1 anti-De Sitter quantum gravity (with space surface of genus g) in the approach of Nelson and Regge.