osp(1|4)Toda模型解的构造

将Leznov–Saveliev代数分析和Drinfeld–Sokolov构造这种方法推广到超对称情形,并运用这种方法给出osp(1|4)Toda模型的解,从而将这种方法推广到二秩情况.     

Quantized (1, 0) ⊕ (0, 1) Fields

We find a mapping between antisymmetric tensormatter fields and the Weinberg 2(2j + 1)-componentbispinor fields. Equations which describethe j = 1 antisymmetric tensor field coincide with the Hammer-Tucker equations entirely and withthe Weinberg ones within a subsidiary condition, theKlein-Gordon equation. A new Lagrangian for the Weinbergtheory is proposed which is scalar and Hermitian. It is built on the basis of the concept ofWeinberg doubles. The origin of acontradiction between the classical theory, the Weinbergtheorem B – A = for quantum relativisticfields, and the claimed longitudity of the antisymmetrictensor field [transformed on the (1, 0) (0, 1)Lorentz group representation] after quantization isclarified. Analogs of the j = 1/2 Feynman–Dysonpropagator are presented in the framework of the j = 1 Weinberg theory.It is then shown that under a definite choice of fieldfunctions and initial and boundary conditions themassless j = 1 Weinberg–Tucker–Hammerequations contain all the information that the Maxwell equationsfor the electromagnetic field have. Thus, the formerappear to be of use in describing some physicalprocesses.     

Bannai–Ito algebras and the universal R-matrix of $$\pmb {\mathfrak {osp}}(1|2)$$osp(1|2)

Letters in Mathematical Physics - The Bannai–Ito algebra BI(n) is viewed as the centralizer of the action of $$\mathfrak {osp}(1|2)$$ in the n-fold tensor product of the universal algebra of...     

The Second-Order Equation from the (1/2, 0) ⊕ (0, 1/2) Representation of the Poincare Group

On the basis of first principles we derive theBarut-Wilson-Fushchich secondorder equation in the (1/2,0) (0, 1/2) representation. Then we discuss thepossibility of describing various mass and spin states in such a framework.     

Beltrami–McKeon–Schubert Realizations of osp(1|4) Algebra and Possible Supersymmetric Kinematics

The possible supersymmetric kinematics are presented by the contraction method in different limits from Beltrami–Mc Keon–Schubert realizations of osp(1|4). The connections among the superalgebras are established. The comparison with the superalgebras contracted from Beltrami–Ivanov–Sorini realization is made.     

Soliton mass and surface tension in the (λ|Ø|4)2 quantum field model

The spectrum of the mass operator on the soliton sectors of the anisotropic (|ø|⁴)₂—and the (ø⁴)₂—quantum field models in the two phase region is analyzed. It is proven that, for small enough >0, the mass gapm _s() on the soliton sector is positive, andm _s()=0(^–1). This involves estimatingm _s() from below by a quantity () analogous to the surface tension in the statistical mechanics of two dimensional, classical spin systems and then estimating () by methods of Euclidean field theory. In principle, our methods apply to any two dimensional quantum field model with a spontaneously broken, internal symmetry group.A Sloan Foundation Fellow; Research supported in part by the U.S. National Science Foundation under Grant No. MPS 75-11864.Supported in part by the National Science Foundation under Grant No. PHY 76-17191     

He-broadening and shifting coefficients of HCl lines in the (1←0) and (2←0) infrared transitions

ABSTRACT

We report experimental results on the broadening and shifting coefficients in a large interval of J quantum numbers in the fundamental and first overtone vibration–rotation bands of the HCl molecule in mixtures with helium. Many of the values, especially for the overtone transition, are novel. The uncertainties for the isotope-averaged broadening coefficients amount to 2% on average for the fundamental and 1.5% for the overtone bands. Shifts have a typical uncertainty of 3%.     

Analytic and numerical evidence from quantum field theory for the hyperscaling relation dv = 2Δ−γ in the d=3 ising model

The hyperscaling relationdv = 2 - (d=3) for the Ising model has been shown to follow from a constructive approach proposed by one of the authors (R.S.) of a relativistic theory of self-interacting Bosons in d space-time dimensions. We present evidence that the two assumptions made in this approach are valid: On a finite Euclidean (hyper-) cubical lattice in d dimensions the renormalization map from the bare to the renormalized parameters should have nonvanishing Jacobian everywhere. We show this analytically and numerically on the boundary set of the parameters. The numerical analysis involves Monte Carlo calculations in the region where the bare coupling constantg ₀ is infinite, giving the Ising model. The linear sizen of the lattice (with periodic boundary conditions) was taken to be 5, 6, and 10. There we also checked the second assumption saying that the correlation length for the Ising model is a monotonic function of the temperature. We also comment on the possible numbers of zeros of the Callan-Symanzik function of this theory.     

Structures and energetics of BenGen (n = 1–5) and Be2nGen (n = 1–4) clusters

Cluster geometries and energies of Be_nGe_n (n = 1–5) and Be_2nGe_n (n = 1–4) have been examined in theoretical electronic structure calculations. Structure optimisations were carried out using DFT B3LYP/6-31G(2df) and the energies of the optimum geometries were ordered in QCISD(T) calculations. Be and Ge bond to each other and to other atoms of their own kind, creating a great variety of low-energy clusters in a variety of structural types. Comparisons of the germanide clusters with previously explored silicide and carbide structures reveal some structural similarities, but the germanides have much more in common with the beryllium silicides than with the carbides. However, germanide clusters show a greater tendency to form cage-like structures with potential in technological applications.     

On the Finite-Dimensional Quantum Group M3⊕(M2|1(Λ2))0

We describe a few properties of the nonsemisimple associative algebra =M₃ (M_2|1 (²))₀, where ² is the Grassmann algebra with two generators. We show that is not only a finite-dimensional algebra but also a (noncommutative) Hopf algebra, hence a finite-dimensional quantum group. By selecting a system of explicit generators, we show how it is related with the quantum enveloping of SL_q(2) when the parameter q is a cubic root of unity. We describe its indecomposable projective representations as well as the irreducible ones. We also comment about the relation between this object and the theory of modular representation of the group SL(2, F₃), i.e. the binary tetrahedral group. Finally, we briefly discuss its relation with the Lorentz group and, as already suggested by A.~Connes, make a few comments about the possible use of this algebra in a modification of the Standard Model of particle physics (the unitary group of the semisimple algebra associated with is U(3) × U(2) × U(1)).     

Photoemission from α and β phases of the GaAs(0 0 1)-c(4 × 4) surface

We prepared α- and β surface phases of GaAs(0 0 1)-c(4 × 4) reconstruction by molecular beam epitaxy (MBE) using As₄ and As₂ molecular beams, respectively, and examined them by angle-resolved ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) with synchrotron radiation as an excitation source. The UPS valence band spectra and the XPS 3d core level data show pronounced differences corresponding to the surface composition and the atomic structure of the two phases, as proposed in the literature. In UPS, the β phase is characterized by an intensive surface state 0.5 eV below the top of the valence band at low photon energy, while an analogous peak in the α phase spectra is missing. The surface state is interpreted in terms of dangling bonds on As dimers. The As3d and Ga3d core level photoelectron lines exhibit phase-specific shapes as well as differences in the number, position and intensity of their deconvoluted components. The location of various atoms in the surface and subsurface layers is discussed; our photoemission results support models of the β phase and the α phase with As-As dimers and Ga-As heterodimers, respectively.     

High-Resolution Spectroscopy of Jet-Cooled (32)SO(2) and (34)SO(2): The ã(3)B(1)-;X(1)A(1), 2(1)(0) and 1(1)(0) Bands

Laser-induced excitation spectra of the two bands ?(3)B(1)-;X(1)A(1), 2(1)(0) and 1(1)(0) of (32)SO(2) and (34)SO(2) have been recorded in a supersonic jet at a resolution of 0.015 cm(-1). The rotational and electron-spin fine structure has been analyzed for both isotopic species. Analysis of the rotational and electron-spin fine structure yields precise values of the rotational constants A, B, and C and the spin constants alpha and beta for both (32)SO(2) and (34)SO(2) in the states ?(3)B(1) (010) and (100). No interaction between these two vibrational states with any nearby triplet state is observed for rotational levels with J 相似文献   

Off-shell Bethe ansatz equation for osp(2∣1) Gaudin magnets

The semi-classical limit of the algebraic Bethe ansatz method is used to solve the theory of Gaudin models. Via off-shell Bethe ansatz method we find the spectra and eigenvectors of the N−1 independents Gaudin Hamiltonians with symmetry osp(2∣1). We also show how the off-shell Gaudin equation solves the trigonometric Knizhnik–Zamolodchikov equation.