On a relation between massive Yang-Mills theories and dual string models

The relations between mass terms in Yang-Mills theories, projective representations of the group of gauge transformations, boundary conditions on vector potentials and Schwinger terms in local charge algebra commutation relations are discussed. The commutation relations (with Schwinger terms) are similar to the current algebra commutation relations of the SU(N) extended dual string model.     

Dual squeezed states

Collective operators corresponding to two different algebras have been introduced for a simple system consisting of a single two-level atom and a high-quality cavity mode. The generators of the first algebra satisfy boson commutation relations, whereas the generators of the second algebra have been obtained by polynomial deformation of su(2) algebra. It has been shown that dual squeezed states identified using the considered commutation relations can be observed in the system placed in an entangled bath with quantum correlations.     

Duality on the quantum space(3) with two parameters

In this study, we introduce a dual Hopf algebra in the sense of Sudbery for the quantum space(3) whose coordinates satisfy the commutation relations with two parameters and we show that the dual algebra is isomorphic to the quantum Lie algebra corresponding to the Cartan-Maurer right invariant differential forms on the quantum space(3). We also observe that the quantum Lie algebra generators are commutative as those of the undeformed Lie algebra and the deformation becomes apparent when one studies the Leibniz rules for the generators.     

OPE formulae for deformed super-Virasoro algebras

We show the OPE formulae for three types of deformed super-Virasoro algebras: the Chaichian-Presnajder deformation, the Belov-Chaltikhian deformation and its modified version. Fundamental (anti-) commutation relations toward a ghost realization of deformed super-Virasoro algebra are also discussed.     

Bogolyubov transformations for regular representations of canonical commutation relations in space with an indefinite metric

Bogolyubov transformations for regular representations of the algebra of canonical commutation relations (CCRs) are considered in space with an indefinite metric.     

Infinite-parameter symmetries and the Higgs effect in gravity-coupled sigma models in D+4 dimensions

We compute the mass spectra of small fluctuations of four-dimensional fields for Kaluza-Klein models in which the compactification from D+4 to 4 (flat) dimensions is induced by the scalar fields of a nonlinear sigma model defined on an S^N or CP^N manifold. The compactifications are stable for all values of N. The fact that the spectra contain no massless vector fields is traced to the absence of a local gauge invariance for the sigma-model action. We introduce a complete basis for the infinite-parameter symmetries that arise from the harmonic analysis of the higher-dimensional dynamical invariances. The spectrum of spin-one and spin-two fields is consistent with the Higgs effect associated with the breaking of the local symmetries corresponding to these generators. The commutation relations of the infinite parameter algebra for the case of CP¹ are also given. The algebra includes the spectrum-generating algebra SO(1,3) of Salam and Strathdee.     

Quantum electrodynamics on a space-time lattice

A Minkowski-lattice version of quantum electrodynamics (or rather its simplified version, with matter described by a scalar field) is constructed. Quantum fields are consequently described in a gauge-independent way, i.e. the algebra of quantum observables of the theory is generated by gauge-invariant operators assigned to zero-, one-, and two-dimensional elements of the lattice. The operators satisfy canonical commutation relations. The uniqueness of representation of this algebra is proved. Field dynamics is formulated in terms of difference equations imposed on the field operators. It is obtained from a discrete version of the path-integral. The theory is local and causal.     

Two-Parameter Deformed Quantum Algebra SUq,s(4)

The commutation relations of thegenerators of the two-parameter deformed quantum algebra SU_q,s(4) are given and irreducible q,s-tensor operators of rank (1/2) of the quantum algebra SU_q,s(2) are constructed.     

The Integrals of Motion for the Deformed W-Algebra $${W_{q,t}(\widehat{gl_N})}$$. II. Proof of the Commutation Relations

We explicitly construct two classes of infinitely many commutative operators in terms of the deformed W-algebra , and give proofs of the commutation relations of these operators. We call one of them local integrals of motion and the other nonlocal, since they can be regarded as elliptic deformations of local and nonlocal integrals of motion for the Virasoro algebra and the W ₃ algebra [1,2]. Dedicated to Professor Tetsuji Miwa on the occasion of the 60th birthday     

Commutation superoperator of a state and its applications to the noncommutative statistics

For a normal state on a von Neumann algebra the space of square-integrable operators is introduced. As distinct from the L² space in the classical probability theory, it possesses an additional skew-symmetric form and the associated superoperator, which is a convenient tool to describe commutation properties in L². It is shown that a state on the algebra of canonical commutation relations is Gaussian (quasi-free) iff the space of canonical observables is an invariant subspace of the corresponding commutation superoperator. Basing on these ideas a new approach to some problems in the noncommutative statistic is developed.     

Scasimir Operator,Scentre and Representations of Uq(osp(1|2))

Recently, Borchers has shown that in a theory of local observables, certain unitary and antiunitary operators, which are obtained from an elementary construction suggested by Bisognano and Wichmann, have the same commutation relations with translation operators as Lorentz boosts and P₁CT operators would have, respectively. It is concluded from this that as soon as the operators considered implement any symmetry, this symmetry can be fixed up to at most some translation. As a symmetry, any unitary or antiunitary operator is admitted under whose adjoint action any algebra of local observables is mapped onto an algebra which can be localized somewhere in Minkowski space.     

Dual squeezed states in an atom-photon cluster and their manifestations

The general kinetic equation for an isolated two-level atom and a high-Q cavity mode in a heat bath exhibiting quantum correlations (entangled bath) is applied to the analysis of the squeezed states of the collective system. Two types of collective operators are introduced for the analysis: one is based on bosonic commutation relations, and the other, on the commutation relations of the algebra obtained by a polynomial deformation of the angular momentum algebra. On the basis of these relations, formulas for observables are constructed that identify squeezed states in the system. It is shown that, under certain conditions, the collective system exhibits dual squeezing within the relations for boson operators, as well as for the operators constructed from the angular momentum algebra. Such squeezing is demonstrated under a projective measurement of an atom and for an entanglement swapping protocol. In the latter case, when measuring two initially independent atomic systems, depending on the type of measurement, two cavity modes collapse into a nonseparable state, which is described either by a nonseparability relation based on boson operators or by a relation based on the operators of the algebra of the quasimomentum of the collective system consisting of these two modes.     

Symmetries of a (2+1)-Dimensional Toda-like Lattice

Lie group technique for solving differential-difference equations is applied to a new (2 1)-dimensional Toda-like lattice. An infinite dimensional Lie algebra and the corresponding commutation relations are obtained.     

Symmetries of a （2＋1）-Dimensional Toda-like Lattice

Lie group technique for solving differential-difference equations is applied to a new (2 1)-dimensional Toda-like lattice. An infinite dimensional Lie algebra and the corresponding commutation relations are obtained.     

Sugawara's construction for Kac-Moody-Malcev algebras

We give a construction of the Virasoro algebra in terms of bilinear combinations of currents. The currents satisfy the Kac-Moody-Malcev commutation relations. The Kac-Moody-Malcev algebras are the generalization of Lie algebras of Kac-Moody type to the Malcev algebras. Thus, we give the generalization of the Sugawara construction to the case of Kac-Moody-Malcev algebras.     

Cubic algebra and averaged Hamiltonian for the resonance 3: (?1) Penning-ioffe trap

For the 3: (?1) resonance Penning trap, we describe the algebra of symmetries which turns out to be a non-Lie algebra with cubic commutation relations. The irreducible representations and coherent states of this algebra are constructed explicitly. The perturbing inhomogeneous magnetic field of Ioffe type, after double quantum averaging, generates an effective Hamiltonian of the trap. In the irreducible representation, this Hamiltonian becomes a second-order ordinary differential operator of the Heun type.     

Analogue of the Weyl representation of algebra of canonical commutation relations in the case of nonphysical particles

An analogue of the Weyl representation of the algebra of canonical commutation relations is proved to exist in the anti-Fock case achieved in Krein space.     

Internal geometry of hadron resonances

Motivated by previous work on high-energy quantum mechanics, a simple model is devised to study the internal geometry of hadron resonances. In this model we assume new basic canonical commutation relations between the (internal) coordinate and momentum operators of the hadronic quantum system. By systematically imposing Lie algebra commutation relations between these and other observables, we discuss the free and bound particle problems, identifying in each case the corresponding internal symmetries. For the bound particle problem, which models quark confinement, this symmetry turns out to be characterized by Dirac's two-oscillator representation of theO(3, 2) de Sitter group.     

Some remarks on producing Hopf algebras

We report some observations concerning two well-known approaches to construction of quantum groups. Thus, starting from a bialgebra of inhomogeneous type and imposing quadratic, cubic or quartic commutation relations on a subset of its generators we come, in each case, to aq-deformed universal enveloping algebra of a certain simple Lie algebra. An interesting correlation between the order of initial commutation relations and the Cartan matrix of the resulting algebra is observed. Another example demonstrates that the bialgebra structure ofsl _q (2) can be completely determined by requiring theq-oscillator algebra to be its covariant comodule, in analogy with Manin's approach to defineSL _q (2) as a symmetry algebra of the bosonic and fermionic quantum planes.Presented at the 4th Colloquium Quantum Groups and Integrable Systems, Prague, 22–24 June 1995.This work was supported in part by International Sciences Foundation (grant RFF-300) and by Russian Basic Research Foundation (grant 95-02-05679).I acknowledge helpful discussions with A. Isaev, P. Kulish, V. Lyakhovsky, O. Ogievetsky, P. Pyatov, and V. Tolstoy.