The q-Boson Realizationo f Parametrized Cyclic Representations of Quantum Superalgebra

By constructing a parametrized cyclic (PC) representation of the q-deformed Heisenberg-Weyl algebras the PC.represen tations of quan tum superalgebra U_qosp(l, 2n) are studied in terms of its q-boson realization. A new type of PC representations of the rank-1 quantum superalgebra U_qosp(l, 2) is obtained by this way.     

The <Emphasis Type="Italic">q</Emphasis>-boson-fermion realizations of the quantum superalgebra <Emphasis Type="Italic">U</Emphasis><Subscript><Emphasis Type="Italic">q</Emphasis></Subscript>(<Emphasis Type="Italic">osp</Emphasis>(1/2))

We show that our construction of realizations for algebras and quantum algebras can be generalized to quantum superalgebras too. We studyan example of quantum superalgebra U _q (osp(1/2)) and give the boson-fermion realization with respect to one pair of q-boson operators and one pair of fermions.     

Extremal projectors for contragredient Lie (super)symmetries (short review)

A brief review of the extremal projectors for contragredient Lie (super)symmetries (finite-dimensional simple Lie algebras, basic classical Lie superalgebras, infinite-dimensional affine Kac-Moody algebras and superalgebras, as well as their quantum q analogs) is given. Some bibliographic comments on the applications of extremal projectors are presented.     

Two Dimensional Cyclic Representations of Uq(sl2)and 8-Vertex Ising Model

We give explicitly the 2-dimensional cyclic representations of quantum algebra U_q(sl₂)with central extension.The intertwiner for tensor representations in different ordersis constructed with C-G coefficients.This intertwiner is shown to be the R -matrix for eight vertex Ising model.     

Multiboson Realization of Two-Mode q-Boson Algebra with suq (2) Covariance

The multiboson realization of two-mode q-boson algebra with su _q (2) covarianceis constructed. A new quantum deformation of su(2) algebra is presented by useof this realization.     

The Construction of q-Boson Realizations and q-Differential Realizations for Quantum Algebras

A general method to construct the q-boson realixations and their corresponding q-differential realizations of quantum algebras is developed with SUq(2) as an example. All poeeible q-boson and q-differential realisations of quantum algebras can be obtained in this way.     

Multiboson Realizations of Lie and Quant urn Algebras

A unified method to construct the (multi-)boson realizations of the Lie and quantum algebras is proposed based on a universal deformation of boson (Heisenberg-Weyl) algebra and its multiboson realization. Some explicit examples, the Lie algebras sl(2) and su (Ill), q-boson algebra, quantum algebras sl(2)_q and su (l,l)_q, along with the q-ladder algebra are studied in detail. In particular, the square boson realizations of su (1,l) and su (l,l)_q are naturally obtained as special cases.     

态|ψ5(3)〉q中广义电场的2(2m+1)次方Y压缩特性

利用多模压缩态理论,研究了由多模复共轭相干态|{Z_j^*}〉_q(j =1,2,3,…,…,q)、多模复共轭相干态的相反态|{-Z_j^*}〉_q和多模虚相干态|{iZ_{j}〉q的线性叠加所组成的第Ⅴ类三态叠加多模叠加态光场|ψ5⁽³⁾〉q中广义电场分量的等幂次N次方Y压缩特性 .结果发现 :当压缩次数N=2 p且p=2m+1(m=0,1,2,…,…)时,在一定的条件下,态|ψ5⁽³⁾〉q的广义电场分量(即第二正交相位分量)可呈现出周期性变化的、偶数次的等幂次2(2m+1)次方Y压缩效应 .}     

Cyclic Representation of the q-Deformed Heisenberg-Weyl Superalgebras and the q-Boson-Fermion Realization of Cyclic Represent at ion of Quantum Superalgebra Uqsl(m,n)

A cyclic representation of the q-deformed Heisenberg-Weyl superalgebras is constructed. By making use of this cyclic representation we study the cyclic representations,of quantum superalgebras in terms of their q-boson-fermion realizations with U_qsl(m, n) as an example. Two different q-boson-fermion realizations of U_qsl(m, n) are used and thus two inequivalent cyclic representations of U_qsl(m, n) are obtained.     

四态叠加多模叠加态光场|Ψe(4),Ⅲ〉q的等阶N次方Y压缩

根据量子力学的线性叠加原理,构造了由多模偶相干态与多模虚偶相干态组成的第Ⅲ种四态叠加多模叠加态光场态|Ψ_e⁽⁴⁾,Ⅲ〉_q的等阶N次方Y压缩特性.结果发现:1) 当压缩阶数N=4m,(m=1,2,3,…)时,态|Ψ_e⁽⁴⁾,Ⅲ〉_q恒处于等阶数N-Y最小测不准态;2) 当压缩阶数N=4m′+2,(m′=0,1,2,…)时,在(θ₁-θ₂),q,R_j,r₁,r₂等取不同的组合定值下,态|Ψ_e⁽⁴⁾,Ⅲ〉_q可分别呈现出等阶N次方Y压缩效应与"半相干态"效应;3) 当压缩阶数N为奇数时,在(θ₁-θ₂),q,R_j,r₁,r₂等取不同的组合定值下,态|Ψ_e⁽⁴⁾,Ⅲ〉_q可呈现出等阶N次方Y压缩效应.     

Irreducible highest weight representations of quantum groupsU q (gl(n,C))

Explicit recurrence formulas of canonical realization (boson representation) for quantum enveloping algebrasU _q (gl(n, C)) are given. Using them, irreducible highest weight representations ofU _q (gl(n, C)) are obtained as restriction of representation of Fock space to invariant subspace generated by vacuum as a cyclic vector.     

On Super-RS Algebra and Drinfeld Realization of Quantum Affine Superalgebras

We describe the realization of the super-Reshetikhin–Semenov-Tian-Shansky (RS) algebra in quantum affine superalgebras, thus generalizing the approach of Frenkel and Reshetikhin to the supersymmetric (and twisted) case. The algebraic homomorphism between the super-RS algebra and the Drinfeld current realization of quantum affine superalgebras is established by using the Gauss decomposition technique of Ding and Frenkel. As an application, we obtain Drinfeld realization of quantum affine superalgebra U_q [osp(1|2)⁽¹⁾] and its degeneration – central extended super-Yangian double DY [osp(12)⁽¹⁾].     

Quantum Lie Algebras, Their Existence, Uniqueness and q-Antisymmetry

Quantum Lie algebras are generalizations of Lie algebras which have the quantum parameter h built into their structure. They have been defined concretely as certain submodules of the quantized enveloping algebras . On them the quantum Lie product is given by the quantum adjoint action. Here we define for any finite-dimensional simple complex Lie algebra an abstract quantum Lie algebra independent of any concrete realization. Its h-dependent structure constants are given in terms of inverse quantum Clebsch-Gordan coefficients. We then show that all concrete quantum Lie algebras are isomorphic to an abstract quantum Lie algebra . In this way we prove two important properties of quantum Lie algebras: 1) all quantum Lie algebras associated to the same are isomorphic, 2) the quantum Lie product of any is q-antisymmetric. We also describe a construction of which establishes their existence. Received: 23 May 1996 / Accepted: 17 October 1996     

多模叠加态光场|ψ5(3)〉q中广义磁场4m次方Y压缩

构造了由多模复共轭相干态|{Z_j^*}〉_q、多模复共轭相干态的相反态|{-Z_j^*}〉_q以及多模虚相干态|{iZ_j^*}〉_q的线性叠加所组成的第Ⅴ类三态叠加多模叠加态光场|ψ₅⁽³⁾〉_q.利用多模压缩态理论研究了态|ψ₅⁽³⁾〉_q中广义磁场分量的等幂次N次方Y压缩特性.结果发现:当压缩次数N=2p且p=2m(m=1,2,3,…,…)时,只要各模的初始相位φ_j(j=1,2,…,…,q)、态间的初始相位差(θ₁-θ₂)、(θ₁-θ₃)和(θ₂-θ₃)以及受各模的初始相位φ_j调制的各单模相干态光场的平均光子数之和 等分别满足一定的取值条件,则态|ψ₅⁽³⁾〉_q的广义磁场分量就可呈现出周期性变化的广义非线性等幂次4m次方Y压缩效应.     

On the defining relations of quantum superalgebras

In defining quantum superalgebras, extra relations need to be added to the Serre-like relations. They are obtained for sl _q (m, n) and osp _q (m, 2n) usingq-oscillator representations.Supported in part by the National Sciences and Engineering Research Council (NSERC) of Canada.     

Quark Condensate in Two-Dimensional SU(NC) Lattice Gauge Theory with Massive Wilson Quarks

Using the improved lattice Hamiltonian with massive Wilson quark and the variational method, we study the quark mass m_q and the Wilson parameter r dependences of the quark condensate 〈ψψ〉in the two-dimensional SU(N_C) lattice gauge theory. The numerical results show that when r is given, for N_C=2,3,4,5,6,7, the value of 〈ψψ〉_suba/(gN_C^3/2) decreases as m_q increases. For N_C>3, when m_q is small, 〈ψψ〉_suba/(gN_C^3/2) is almost independent of r; when m_q is large, 〈ψψ〉_suba/(gN_C^3/2)increases with increasing r. Particularly, when m_q→0, our numerical results agree very well with Zhitnitsky's analytical weak coupling result in the continuum, which implys that our numerical results in the case of m_q≠0 are reliable.     

On Centralizer Algebras for Spin Representations

We give a presentation of the centralizer algebras for tensor products of spinor representations of quantum groups via generators and relations. In the even-dimensional case, this can be described in terms of non-standard q-deformations of orthogonal Lie algebras; in the odd-dimensional case only a certain subalgebra will appear. In the classical case q?= 1 the relations boil down to Lie algebra relations.     

Inhomogeneous q-Differential Realization,Inhomogeneous q-Boson Realization of Quantum Group SU(n)q and Its Indecomposable Representations

An inhomogeneous q-differential realization (q-IHDR) and its corresponding inhomogeneous q-boson realization (q-IHBR) of quantum group SU(n)_q are studied. By making use of the q-IHBR a kind of infinite dimensional indecomposable and irreducible representations of SU(n)_q is studied on the q-Fcck space. The finite dimensional irreducible representations of SU(n), are obtained on the finite dimensional subspaces of q-Fock space. As an example, these representations of SU(2)_q are studied in detail and Jimbo standard irreducible representations are obtained.     

The cyclic representations of the quantum superalgebra U q osp(2, 1) withq a root of unity

By generalizing De Concini and Kac's cyclic representation theory of quantum groups at roots of unity, the cyclic representations of the quantum superalgebra U _q osp(2, 1) are constructed in three classes: irreducible representations with single multiplicities, irreducible representations with the multiplicities larger than one, and indecomposable representations.This work is supported in part by the National Sciene Foundation in China.     

Relating the approaches to quantised algebras and quantum groups

This paper constructs two representations of the quantum groupU _q g' by exploiting its quotient structure and the quantum double construction. Here the quantum group is taken as the dual to the quantised algebraU _q g, a one parameter deformation of the universal enveloping algebra of the Lie algebra g, as in Drinfel'd [6] and Jimbo [10]. From the two representations, the Hopf structure of the quantised algebraU _q g is reexpressed in a matrix format. This is the very structure given by Faddeev et al. [7], in their approach to defining quantum groups and quantised algebras via the quantisation of the function space of the associated Lie group to g.Supported by a SERC studentship