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1.
We discuss finite action solutions ofP n–1 models, of their Grassmannian generalizations and of a classical fermion — boson model based on the supersymmetric extension of theP n–1 model.Invited talk presented at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–19, 1981.I would like to thank Dr. A. M. Din for his collaboration with me on all the topics discussed here. Also I would like to thank E. F. Corrigan, D. B. Fairlie, M. Günyadin, J. Lukierski, I. Singer, R. Stora and many others for discussions and constructive criticisms and Professor J. Niederle for his invitation to present this talk at the symposium and for hospitality in Czechoslovakia.  相似文献   

2.
We investigate the algebras of the non-local charges and their generating functionals (the monodromy matrices) in classical and quantum non-linear models. In the case of the classical chiral models it turns out that there exists no definition of the Poisson bracket of two monodromy matrices satisfying antisymmetry and the Jacobi identity. Thus, the classical non-local charges do not generate a Lie algebra. In the case of the quantum O(N) non-linear model, we explicitly determine the conserved quantum monodromy operator from a factorization principle together withP,T, and O(N) invariance. We give closed expressions for its matrix elements between asymptotic states in terms of the known two-particleS-matrix. The quantumR-matrix of the model is found. The quantum non-local charges obey a quadratic Lie algebra governed by a Yang-Baxter equation.Laboratoire associé au CNRS No. LA 280  相似文献   

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We compare some of the properties of P 2 with those of the SU(2) Yang-Mills Instanton and conclude that P 2 may be regarded as a gravitational pseudoparticle surrounded by an event horizon.  相似文献   

5.
It is proved that the moduli space of static solutions of the P 1 model on spacetime ×, where is any compact Riemann surface, is geodesically incomplete with respect to the metric induced by the kinetic energy functional. The geodesic approximation predicts, therefore, that lumps can collapse and form singularities in finite time in these models.  相似文献   

6.
In this paper, based on N-soliton solutions, we introduce a new constraint among parameters to find the resonance Y-type soliton solutions in (2+1)-dimensional integrable systems. Then, we take the (2+1)-dimensional Sawada–Kotera equation as an example to illustrate how to generate these resonance Y-type soliton solutions with this new constraint. Next, by the long wave limit method, velocity resonance and module resonance, we can obtain some new types of hybrid solutions of resonance Y-type solitons with line waves, breather waves, high-order lump waves respectively. Finally, we also study the dynamics of these interaction solutions and indicate mathematically that these interactions are elastic.  相似文献   

7.
Level densities are required at excitation energies where discrete level information is not available or incomplete to get a reliable theoretical analysis of cross sections, spectra, and angular distributions. The total reaction cross sections of some lanthanides (141Pr, 142Nd, 144Sm, 153Eu, 160Gd, 159Tb, 165Ho, 175Lu) were calculated using TALYS 1.2 code for gamma-induced reactions through the five level density models in the incident gamma energy range from 5 to 30 MeV. All calculations from the present study were compared with each other and with the experimental data obtained from EXFOR library. The total photo-neutron reaction cross-section values obtained from the model calculations and experimental measurements taken from EXFOR confirm the presence of systematical disagreements reported in the literature, except 165Ho case where one can see a satisfactory agreement.  相似文献   

8.
In this paper we will study the nonlinear Schrödinger equations: $$\begin{gathered} i\partial _t u + \tfrac{1}{2}\Delta u = \left| u \right|^2 u, (t,x) \in \mathbb{R} \times \mathbb{R}_x^n , \hfill \\ u(0,x) = \phi (x), x \in \mathbb{R}_x^n \hfill \\ \end{gathered} $$ . It is shown that the solutions of (*) exist and are analytic in space variables fort∈??{0} if φ(x) (∈H 2n+1,2(? x n )) decay exponentially as |x|→∞ andn≧2.  相似文献   

9.
Using a cosmological black hole model proposed recently, we have calculated the quasi-local mass of a collapsing structure within a cosmological setting due to different definitions put forward in the last decades to see how similar or different they are. It has been shown that the mass within the horizon follows the familiar Brown–York behavior. It increases, however, outside the horizon again after a short decrease, in contrast to the Schwarzschild case. Further away, near the void, outside the collapsed region, and where the density reaches the background minimum, all the mass definitions roughly coincide. They differ, however, substantially far from it. Generically, we are faced with three different Brown–York mass maxima: near the horizon, around the void between the overdensity region and the background, and another at cosmological distances corresponding to the cosmological horizon. While the latter two maxima are always present, the horizon mass maxima is absent before the onset of the central singularity.  相似文献   

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The approximate analytical solutions of the Dirac equation with the Pschl-Teller potential is presented for arbitrary spin-orbit quantum number κ within the framework of the spin symmetry concept.The energy eigenvalues and the corresponding two Dirac spinors are obtained approximately in closed forms.The limiting cases of the energy eigenvalues and the two Dirac spinors are briefly discussed.  相似文献   

12.
The transcendence and algebraic independence of some p-adic series and of the values of analytic functions of series of this kind are studied.  相似文献   

13.
A classical model of the triatomic D?? molecule subjected to an intense, few-cycle laser pulse is introduced. The model is capable of describing the laser-induced correlated motion of both electrons and nuclei in three dimensions, and allows us to follow the motion of the two electrons and three deuterons from the initial field-free state, during the pulse, and until the bond breaking into the final fragments. By averaging over many trajectories, we calculate the relative yields of the ionization and dissociation channels, as well as the kinetic energy release (KER) from the fragment ions. A comparison with recent experimental KER spectra shows good qualitative agreement. In addition, we find a pathway in which an emitted electron recombines into a high-lying Rydberg state, resulting in D + D? + D? fragments with the same KER as in the D? + D? + D? channel.  相似文献   

14.
The equations obtained by Yang while discussing the condition of self-duality of SU(2) gauge fields on Euclidean four-dimensional space have been generalized. Exact solutions and their graphical representations for the generalized equation (for some particular values of the parameters) have been reported. They represent interesting physical characteristics like waves with spreading solitary profile, spreading wave packets, waves with pulsating solitary profile (between zero and a maximum), waves with oscillatory solitary profile and chaos.   相似文献   

15.
The photoluminescence method was used in the temperature range of 15?C300 K to study the optical properties of quantum-dimensional heterostructures based on GaN x As y P(1?x?y) solid solutions, synthesized on the surface of a GaP (100) substrate. The calculations for the band-gap width of the GaN x As y P(1?x?y) solid solution with the use of the band anticrossing model are shown to agree well with experimental data.  相似文献   

16.
Motivated by the operator formulation of conformal field theory on Riemann surfaces, we study the properties of the infinite dimensional group of local biholomorphic transformations (conformal reparametrizations) of 1 and develop elements of its representation theory.  相似文献   

17.
Making an ansatz to the wave function, the exact solutions of the D-dimensional radial Schrödinger equation with some molecular potentials, such as pseudoharmonic and modified Kratzer, are obtained. Restrictions on the parameters of the given potential, δ and ν are also given, where η depends on a linear combination of the angular momentum quantum number ? and the spatial dimensions D and δ is a parameter in the ansatz to the wave function. On inserting D = 3, we find that the bound state eigensolutions recover their standard analytical forms in literature.  相似文献   

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We explore a particular way of reformulating quantum theory in classical terms, starting with phase space rather than Hilbert space, and with actual probability distributions rather than quasiprobabilities. The classical picture we start with is epistemically restricted, in the spirit of a model introduced by Spekkens. We obtain quantum theory only by combining a collection of restricted classical pictures. Our main challenge in this paper is to find a simple way of characterizing the allowed sets of classical pictures. We present one promising approach to this problem and show how it works out for the case of a single qubit.  相似文献   

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