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1.
Tensor Polarization t20 of the deuteron is calculated on the basis of a hybrid quark-hadron model.A relativistic wavefunction of the deuteron is used to calculate the relativistic impulse approximation and the contribution of the ρπγ meson exchange process.A good agreement with experimental data is achieved when and only when the ρπγ coupling is taken as positive.  相似文献   

2.
In this work, we study the quasinormal modes (QNMs) of scalar field coupling to Einstein’s tensor in charged braneworld black hole. The shape of the potential function is illustrated and we find that lower coupling constant leads to more stable field. We then apply six-order WKB approximation to calculate the quasinormal frequencies (QNF) in weaker coupling field, and depict the dependence of the oscillation frequency on the coupling constant. Furthermore, we use finite difference method to shape the evolution of the coupling field and find that coupling field with lower multipole numbers l corresponds to stable field, while higher l tends to lead to instability when the coupling constant is larger than a threshold value. Finally the fitting curve of such threshold value is given numerically.  相似文献   

3.
It has been shown that the following modification of the symmetric (Gilbert) total energy–momentum tensor (EMT) density \({t^{\mu v}} \to {t^{\mu v}} - \frac{{{m^2}}}{{16\pi G}}{\tilde \varphi ^{\mu v}}\) leads to incorrect results in basic energetic calculations. It is pointed out that some attempts to prove the positive definiteness of the gravitational radiation flux in the RTG are based on the nonconservative energy–momentum tensor.  相似文献   

4.
The real scalar field equation between the outer black hole horizon and the cosmological horizon is solved in the Reissner-Nordstroem-de Sitter space when it is at the phase transition point. We use an accurate approximation,the polynomial approximation, to approximate the tortoise coordinate x(r) for obtaining the inverse function r=r(x) and then for solving the wave equation. The case where the two horizons are very close to each other is discussed in detail. It is found that the wave function is characteristically similar to the harmonic in the whole range with x as the independent coordinate, while the waves pile up near the horizons with r as the independent coordinate. Furthermore, we find that the height of the potential increases as the cosmological constant A decreases.  相似文献   

5.
Scalar Approximation of Super-Gaussian Beams   总被引:1,自引:0,他引:1  
1IntroductionThemodesofacavitywithsuperGausianreflectivityareknownassuperGausianbeams,theydescribeawholefamilyoffielddistri...  相似文献   

6.
段一士  杨捷 《中国物理快报》2005,22(5):1079-1082
Using the decomposition theory of U(1) gauge potential and b-mapping topological current theory, we investigate the topological inner structure of Chern Simons tensor current. It is proven that the U(1) Chern-Simons tensor current in four-dimensional manifold is just the topological current of creating the string world-sheets.  相似文献   

7.
The relativistic momentum approximation has been used to calculate the tensor analyzing capacity F20 of the d p reaction. At high proton moments (p50 MeV/sec), the dependence of F20 of the parameters of the n vertex becomes substantial, which shows that experiments on F20 can provide information on the electromagnetic form factor of the n transition.Research performed with financial support from the Russian Fundamental Research Fund (project code 93-02-3514).Nuclear Physics Research Institute, Tomsk Polytechnical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 35–38, October, 1994.  相似文献   

8.
We give the approximate analytic solutions of the Dirac equation for the Deng Fan potential. After a Pekeris-type approximation, we bring the problem into a Schrödinger-like equation and obtain the spectrum of the system via supersymmetry quantum mechanics. Some numerical comments are given on the energy spectrum.  相似文献   

9.
We apply the effective potential method to study the vacuum stability of the bounded from above (?? 6) (unstable) quantum field potential. The stability (?E/?b = 0) and the mass renormalization (? 2 E/?b 2 = M 2) conditions force the effective potential of this theory to be bounded from below (stable). Since bounded from below potentials are always associated with localized wave functions, the algorithm we use replaces the boundary condition applied to the wave functions in the complex contour method by two stability conditions on the effective potential obtained. To test the validity of our calculations, we show that our variational predictions can reproduce exactly the results in the literature for the \(\mathcal {PT}\) -symmetric ? 4 theory. We then extend the applications of the algorithm to the unstudied stability problem of the bounded from above (?? 6) scalar field theory where classical analysis prohibits the existence of a stable spectrum. Concerning this, we calculated the effective potential up to first order in the couplings in d space-time dimensions. We find that a Hermitian effective theory is instable while a non-Hermitian but \(\mathcal {PT}\) -symmetric effective theory characterized by a pure imaginary vacuum condensate is stable (bounded from below) which is against the classical predictions of the instability of the theory. We assert that the work presented here represents the first calculations that advocates the stability of the (?? 6) scalar potential.  相似文献   

10.
We study the direct interaction of an antisymmetric Kalb–Ramond field with a scalar particle derived from a gauge principle. The method outlined in this paper to define a covariant derivative is applied to a simple model leading to a linear coupling between the fields. Although no conserved Noether charge exists, a conserved topological current comes out from the antisymmetry properties of the Kalb–Ramond field. Some interesting features of this current are pointed out. Possible applications of our results to cosmology and to the theory of three-dimensional Josephson junction arrays are envisaged.  相似文献   

11.
Wavefunctions and the electromagnetic form factor of charged scalar mesons are studied with the vector-vectortype fiat-bottom potential model under the framework of the spinor-spinor Bethe-Salpeter equation. The obtained results are in agreement with other theories.  相似文献   

12.
The scalar field model of dark energy is established in the double complex symmetric gravitational theory. The universe we live in is taken as the real part of double complex space M^4C(J). The two cases of scalar field (ordinary and phantom scalar field) are discussed in a unified way. Not only can the double Friedmann equations be obtained, but also the equation of state for dark energy, potential V(φ) and scalar field φ can be expressed. Hence, a new method is proposed to study dark energy and the evolution of the universe.  相似文献   

13.
We study the energy level shifts of an accelerated multilevel atom in dipole coupling to the derivative of a quantum massless scalar field and separately calculate the contributions of vacuum fluctuations and radiation reaction to the shifts. It is found that, in contrast to the case of a monopole-like interaction, both the vacuum fluctuations and radiation reaction contributions are changed by acceleration, and they all contain non-thermal correction terms. Our results suggest that the effect of acceleration on the energy shifts is dependent on the type of the interaction between the atom and the quantum field.  相似文献   

14.
By using the third-order Wentzel-Kramers-Brillouin approximation and the monodromy methods, the quasnormal modes of a coupled scalar field in the canonical non-rotating acoustic black hole spacetime are investigated. It is shown that the coupling between the scalar field and background metric affects the quasinormal frequencies. At low overtones, both the real part and the magnitude of imaginary part increase with the couple factor ξ. For the larger ξ, both of them are almost linearly related to the couple factor. At high overtones, it is found that the frequency formula of the quasinormal modes is 2πω/κ = ln ( 1 + 2 cos√9-24ξ/5 π) - i(2n + 1)π, which means that 5 when ξ is larger, the real part is the linear function of ξ^1/2.  相似文献   

15.
It has been pointed out by Hall et al. [Gen. Rel. Gray. 28 (1996) 299.] that matter collineations can be defined by using three different methods. But there arises the question whether one studies matter collineations by using LεTab=0, or LεT^ab = 0 or LεT^b a=0. These alternative conditions are, of. course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition.  相似文献   

16.
A supersymmetric technique for the bound-state solutions of the s-wave Klein-Gordon equation with equal scalar and vector standard Eckart-type potential is proposed. Its exact solutions are obtained. Possible generalization of our approach is outlined.  相似文献   

17.
The Yang–Mills system of field equations which includes coupling to an SU(2) scalar matter doublet is developed. It is shown that an SU(2) current for a scalar matter doublet can be developed. The basic structure which fits the Yang–Mills system is somewhat different from the case of the scalar triplet. Using this form for the scalar current, it is possible to write down the Yang–Mills system which couples to the scalar matter doublet. It is shown that several sets of solutions to this system of equations can be obtained.  相似文献   

18.
The energy transfer of homogeneous scalar turbulence is studied numerically by triad interaction in spectral space. The different transfer properties between turbulent kinetic energy and turbulent scalar energy reveal that non-local energy transfer exists as important as the local energy transfer in scalar turbulence. The non-local energy transfer of scalar turbulence results from non-local triad interaction. As a result there will be longer inertiaconvective range in scalar turbulence than the inertial subrange in turbulent kinetic transfer at Reλ = Peλ. The non-local transfer of turbulent scalar energy generates more energy transfer into dissipation range. The discovery of non-local transfer of turbulent scalar energy indicates that this phenomenon should be concerned carefully in numerical scheme and subgrid modelling of direct numerical simulation or large eddy simulation scalar turbulence.  相似文献   

19.
We give a construction of the stress–energy tensor of conformal field theory (CFT) as a local “object” in conformal loop ensembles CLE κ , for all values of κ in the dilute regime 8/3 < κ ≤ 4 (corresponding to the central charges 0 < c ≤ 1 and including all CFT minimal models). We provide a quick introduction to CLE, a mathematical theory for random loops in simply connected domains with properties of conformal invariance, developed by Sheffield and Werner (Ann Math 176, 1827–1917, 2012). We consider its extension to more general regions of definition and make various hypotheses that are needed for our construction and expected to hold for CLE in the dilute regime. Using this, we identify the stress–energy tensor in the context of CLE. This is done by deriving its associated conformal Ward identities for single insertions in CLE probability functions, along with the appropriate boundary conditions on simply connected domains; its properties under conformal maps, involving the Schwarzian derivative; and its one-point average in terms of the “relative partition function”. Part of the construction is in the same spirit as, but widely generalizes, that found in the context of SLE8/3 by the author, Riva and Cardy (Commun Math Phys 268, 687–716, 2006), which only dealt with the case of zero central charge in simply connected hyperbolic regions. We do not use the explicit construction of the CLE probability measure, but only its defining and expected general properties.  相似文献   

20.
This article discusses the role of covariance correlation tensor in the establishment of the criterion of quantum entanglement. It gives a simple example to show the powerfulness in the treatment of quantum dense coding, and illustrates the fact that this method also provides theoretical basis for establishing corresponding knotted pictures.  相似文献   

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