Simultaneous SO(2n) generator measurement by spin-clifford algebra coupling

In this paper we generalize the theory of simultaneous spin-component measurement to an arbitrary SO(2n) algebra. Independent (meter) spin-1/2 particles are coupled to the generators of the corresponding SO(2n) Clifford algebra. Assuming all meter particles are aligned initially in they direction, it is shown that the measurement of the meterx components after system coupling results in a simultaneous measurement of the system SO(2n) operators.     

Graph theory,SO(n) current algebra and the Virasoro master equation

We announce an isomorphism between a set of generically irrational affine-Virasoro constructions onSO(n) and the unlabelled graphs of ordern. On the one hand, the conformal constructions are classified by the graphs, while, conversely, a group-theoretic and conformal field-theoretic identification is obtained for every graph of graph theory. High-level expansion provides a strong argument that each construction is unitary down to some finite critical level.This work was supported in part by the Director, Office of Energy Research, Office of High Energy and Nuclear Physics, Division of High Energy Physics of the U.S. Department of Energy under Contract DE-AC03-76SF00098 and in part by the National Science Foundation under grant PHY85-15857     

Magnetic Properties of SO(5) Superconductivity

The distinction between type I and type II superconductivity is reexamined in the context of the SO(5) model recently put forth by Zhang. Whereas in conventional superconductivity only one parameter (the Ginzburg-Landau parameter κ) characterizes the model, in the SO(5) model there are two essential parameters. These can be chosen to be κ and another parameter, β, related to the doping. There is a more complicated relation between κ and the behavior of a superconductor in a magnetic field. In particular, one can find type I superconductivity, even when κ is large, for appropriate values of β.     

Spinless Excitons Implicit in SO(5) Theory

A pair of up-down operators are constructed explicitly for S.C.Zhang's SO(5) theory of high T_c superconductivity.From them two good quantum numbers are derived.The up-down operators are related to the spin-independent excitons which are not considered before.     

Spinless Excitons Implicit in SO(5) Theory

A pair of up-down operators are constructed explicitly for S.C.Zhang‘s SO(5) theory of high Tc superconductivity.From them two good quantum numbers are derived.The up-down operators are related to the spin-independent excitons which are not considered before.``     

Extended supergravity with local SO(5) invariance

We present a version of N = 5 supergravity with local SO(5) invariance and a lowest order calculation for N = 8 supergravity with local SO(8). The implications of these results and related aspects are discussed.     

A model for so(5) = sp(4) lie algebra

The paper is the continuation of a previous one [Physica Scripta22 (1980), 545–555] devoted to quadrupling in the shell model. We consider here a simple model of the ten- dimensional quasi-spin Lie algebra which is spectrum generating for the quadrupling Hamiltonian. The model allows us to investigate many concrete aspects of the theory of linear representations of the quasi-spin algebra. In particular, we present an explicit construction of the irreducible representation module for the finite dimensional representations, and we consider the direct product of the such irreducible modules.     

Deformation of the exterior algebra Ω(M n) and the Yang-Baxter equation

We show that the deformation of the exterior algebra on a given manifold is related to the existence of the Yang-Baxter equation. We prove that this deformed algebra involves a differential operator generating the algebra. The obtained differential calculus is not commutative and we recover the classical one for the classical limit of the deformation parameters. The q-analogue of the Leibniz rule corresponding to the purposed differential operator is given.     

Square-lattice algebraic spin liquid with SO(5) symmetry

We propose a critical spin liquid ground state for S=1/2 antiferromagnets on the square lattice. In a renormalization group analysis of the "staggered flux" algebraic spin liquid, we examine perturbations, present in the antiferromagnet, which break its global SU(4) symmetry to SO(5). At physical parameter values, we find an instability towards a fixed point with SO(5) symmetry. We discuss the possibility that this fixed point describes a transition between the Néel and valence bond solid states, and the relationship to the SO(5) nonlinear sigma model of Tanaka and Hu.     

Coupling Coefficients of Quasispin Group SO(5)t

A recurrent method for coupling coefficient calculations of five-dimensional quasispin group SO(5)_t is proposed. The explicit coupling coefficients such a .     

Four-dimensional heterotic string models with SU(5) and SO(10) grand unification

The gauge group, quark and lepton generations, Higgs scalar structure, couplings of quarks and leptons to Higgs scalars and to colour triplet scalars, and the gauge symmetry breaking are studied for a class of four-dimensional heterotic string models whose boundary conditions include third-integral twists.     

SO(5, 1) dynamical symmetry for electron Zitterbewegung

Electron rest-frame internal canonical coordinates are reobtained by the free-particle Foldy-Wouthuysen transformation: Schrödinger microscopic momentum, Barut-Bracken microscopic coordinate, and the rest Hamiltonian, which describe Zitterbewegung in this frame.SO(4, 1) Snyder space-time invariant quantization is considered in order to construct a dynamical group for Zitterbewegung. The electron's internal structure appears associated with its secondorder self-energy process and governed by the 15-parameter dynamical groupSO(5, 1). This is a generalization of Barut-Bracken symmetry which describes Zitterbewegung as generated by an algebra of the rotation groupSO(5). This noncompact symmetrySO(5, 1) permits a natural interpretation for the operators of its algebra and introduces a generalization to higher-dimensional fermionic representations.     

Bicritical and tetracritical phenomena and scaling properties of the SO(5) theory

By Monte Carlo simulations on a 3D SO(5) rotator model it is shown that, in contrast to the epsilon expansions of the renormalization group, the bicritical point is stable to biquadratic perturbations of AF-SC (antiferromagnetism-superconductivity) repulsions, which are produced by quantum fluctuations originated from the Gutzwiller projection. Therefore, the present work completes the link from a physical projected SO(5) starting point to an asymptotic SO(5) symmetry point. The tetracritical point is stable for attractive AF-SC interactions. Critical exponents and ratios are evaluated by scaling analysis. Bicritical and tetracritical scaling functions are derived for the first time. Suggestions on experiments are given.     

A unified treatment of the groups SO(4) and SO(3,1)

The irreducible representations of the group SO(4) in which the SO(3) subgroup is reduced are studied by an explicit construction of the operators and the basis in the spinor representation. The basis function which is formally identical with that for the coupling of two angular momentaj ₁ andj ₂ is expressible in terms of a hypergeometric function and strongly resembles the one for the irreducible representations of the groups SO(3,1). For the Lorentz group, the bases for the unitary representations which require unphysical values ofj ₁ andj ₂ are found to be analytic continuation of those for SO(4). The realization of the unitary irreducible representations of the group SO(4) in the Hilbert space of these functions leads, for appropriate unphysical values ofj ₁,j ₂, to the Gelfand-Naimark formula for the principal and complementary series of the representations of SO(3;1). The matrix elements for finite transformations of SO(4) and SO(3,1) can be evaluated, in this approach, in a unified manner by using standard properties of the hypergeometric function. These turn out to be a finite sum of₃ F ₂-functions which, as expected, are polynomials for SO(4) and infinite series for SO(3,1). A number of special matrix elements are calculated from the general formula and these agree with the results obtained previously.The authors are deeply indebted to Professor S.Dutta Majumdar fo many important suggestions and clarifications.     

Preons and SO(10)

Two composite models based on SO(10) are explored, the first containing a fermion and a scalar each in the 16 rep, the second containing two fermion reps 10 + 16. The second model contains a massless composite fermion in the confined picture with a Higgs picture interpretation.     

sl(N) Onsager's algebra and integrability

We define ansl(N) analog of Onsager's algebra through a finite set of relations that generalize the Dolan-Grady defining relations for the original Onsager's algebra. This infinite-dimensional Lie algebra is shown to be isomorphic to a fixed-point subalgebra ofsl(N) loop algebra with respect to a certain involution. As the consequence of the generalized Dolan-Grady relations a Hamiltonian linear in the generators ofsl(N) Onsager's algebra is shown to posses an infinite number of mutually commuting integrals of motion.     

Enhancement factors for supersymmetric proton decay in SU(5) and SO(10) with superfield techniques

The anomalous dimensions of the proton decay operators of dimension six are calculated in supersymmetric SU(5) and SO(10) with superfield techniques. The corresponding enhancement factors are remarkably similar in both cases and practically identical to the non-supersymmetric case. Also results are given for the enhancement factors of the dimension-five operators for both unification groups.     

Flipped SO(10)

We constract an N = 1 supersymmetric SO(10) GUT broken down to SU(3)_c×SU(2)_L×U(1)_Y with an intermediate flipped SU(5)×U(1)_X gauge symmetry. A solution to the triplet-doublet mass-splitting problem is proposed in terms of a non-minimal missing-partner mechanism.     

Quantum deformedsu(m/n) algebra and superconformal algebra on quantum superspace

We study a deformedsu(m/n) algebra on a quantum superspace. Some interesting aspects of the deformed algebra are shown. As an application of the deformed algebra we construct a deformed superconformal algebra. From the deformedsu(1/4) algebra, we derive deformed Lorentz, translation of Minkowski space,iso(2, 2) and its supersymmetric algebras as closed subalgebras with consistent automorphisms.