共查询到20条相似文献,搜索用时 13 毫秒
1.
2.
A Chouchaoui 《Annals of Physics》2004,312(2):431-440
The propagator related to the Calogero potential is calculated in the phase space by way of Feynman formalism. The energy spectrum is determined along with the corresponding wave functions. In case some constraints are introduced, the problem may be reduced to the one corresponding to a particle constrained to move into a sector of opening angle α. It is shown as well that complicated potentials, may be transformed to allow the calculation of the energy spectrum via the Kleinert method. 相似文献
3.
In this paper we propose a modification of the relationship between a short-time propagator and a corresponding classical lagrangian. This modification enables us, in a simple way, to construct path integrals for configuration spaces with boundaries where we have to take into account boundary conditions imposed on the propagator. Simple examples are added as illustrations. 相似文献
4.
Gouranga C. Nayak 《The European Physical Journal C - Particles and Fields》2009,59(4):891-898
In this paper we implement the Schwinger–Keldysh closed-time path integral formalism in non-equilibrium QCD in accordance
to the definition of the Collins–Soper fragmentation function. We consider a high-p
T parton in QCD medium at initial time τ
0 with an arbitrary non-equilibrium (non-isotropic) distribution function
fragmenting to a hadron. We formulate the parton-to-hadron fragmentation function in non-equilibrium QCD in the light-cone
quantization formalism. It may be possible to include final-state interactions with the medium via a modification of the Wilson
lines in this definition of the non-equilibrium fragmentation function. This may be relevant to the study of hadron production
from a quark–gluon plasma at RHIC and LHC. 相似文献
5.
V. N. Ivanov 《Russian Physics Journal》1998,41(7):667-671
We investigate the relationship between the density matrix formalism and the method of describing quantum systems with wave
functions pre-averaged over the thermostat states. It is shown that when fluctuations of the perturbation operator have a
duration less than that of the characteristic times of variation of the isolated subsystem and the density matrix of the entire
system can be represented as a direct product of the density matrix of the subsystem and the density matrix of the surrounding
medium, both approaches lead to Neumann equations of the same structure.
Omsk State Technical University. Translated fromIzvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 64–68, July, 1998. 相似文献
6.
S. V. Shevkunov 《Journal of Experimental and Theoretical Physics》2008,106(1):17-33
Fundamental relations between ensemble-averaged kinetic energy, pressure, and virial are obtained for quantum many-particle systems at finite temperatures. A path-integral method is developed for calculating kinetic energy for mixed (quantum-classical) systems. The method eliminates the problem of divergent variance. Path-integral Monte Carlo simulations are performed to validate the method as applied to single-electron and electron-pair wave packets, with exact treatment of exchange symmetry and spin states. Quantitative results are compared with corresponding characteristics calculated for point charges. 相似文献
7.
D. V. Olenev É. I. Isaev Yu. Kh. Vekilov 《Journal of Experimental and Theoretical Physics》1998,86(3):550-558
Electron spectra and wave functions of icosahedral quasicrystals have been investigated in the tight-binding approximation
using the two-fragment structural model (the Amman-MacKay network) with “central” decoration. A quasicrystal has been considered
as a limiting structure in a set of optimal cubic approximants with increasing lattice constants. The method of level statistics
indicates that the energy spectrum of an icosahedral quasicrystal contains a singular (nonsmooth) component. The density of
electron states has been calculated for the first four optimal cubic approximants of the icosahedral quasicrystal, and the
respective Lebesgue measures of energy spectra of these approximants have been obtained. Unlike the case of a one-dimensional
quasiperiodic structure, the energy spectrum of an icosahedral quasicrystal does not contain a hierarchical gap structure
typical of the Cantor set of measure zero in a one-dimensional quasicrystal. Localization of wave functions in an icosahedral
quasicrystal has been studied, and their “critical” behavior has been detected. The effect of disorder due to substitutional
impurities on electron properties of icosahedral quasicrystals has been investigated. This disorder makes the electron spectrum
“smoother” and leads to a tendency to localization of wave functions.
Zh. éksp. Teor. Fiz. 113, 1009–1025 (March 1998) 相似文献
8.
V. A. Zilitis 《Russian Physics Journal》1978,21(12):1554-1558
The system of equations for radial wave functions is written in a form allowing both relativistic and non relativistic wave functions to be obtained. In the case of a discrete spectrum, an asymptotic solution of this system is obtained for a potential which includes not only a Coulomb term but also terms corresponding to dipole and quadrupole polarization. The normalizing factor of the asymptote is determined in the approximation of the relativistic quantum-defect method, which offers the possibility, in principle, of using the functions in semiempirical calculations analogous to nonrelativistic calculations by the Bates — Damgaard — Seaton method. The calculation scheme is illustrated for the example of the calculation of Si IV wave functions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 39–44, December, 1978. 相似文献
9.
H.S. Sharatchandra 《Physics letters. [Part B]》1978,77(2):185-187
It is pointed out that the leading singularity of e?βH at β = 0 comes from just the zero frequency mode in the path integral. The WKB energy levels and corrections to it can therefore easily be estimated. However, the method works only for potentials unbounded at infinity. 相似文献
10.
J. Dušek 《Czechoslovak Journal of Physics》1983,33(7):745-756
For two inhomogeneous Schrödinger equations playing an important role within the framework of the Gell-Mann — Goldberger two-potential formalism we derive the integral equations for the off-shell solutions and give the relations between the regular and Jost solutions. We define the Jost functions fully off the energy shell. The obtained formulae give the possibility to extend the validity of various useful relations derived within the one-potential theory. 相似文献
11.
The hopping conductivity σ3 has been studied in samples of slightly counterdoped crystalline Si: B with a boron concentration of 2×1016 cm?3<N<1017 cm?3 and a compensation of 10?4≤K≤10?2. It is found that at K≤10?3 the activation energy ε3 is not lower (as it must be according to classical notions at finite K) but larger than the value εN=e 2 N 1/3/κ, where e is the electronic charge and κ is the dielectric constant. With decreasing N, the energy ε3 drops slower and, with decreasing K, grows faster than follows from the standard theory. At K≤10?4, ε3 is higher than ε N by a factor of 1.5–2. The result is explained by the effect of the overlap between wave functions of neighboring impurity centers on the structure of the impurity band. 相似文献
12.
The general formulation of a technically advantageous method to find the ground state solution of the Schrödinger equation in configuration space for systems with a number of particles A greater than 4 is presented. The wave function is expanded in pair-correlated hyperspherical harmonics beyond the lowest order approximation and then calculated in the Faddeev approach. A recent efficient recursive method to construct antisymmetric A-particle hyperspherical harmonics is used. The accuracy is tested for the bound state energies of nuclei with A = 6–12. The high quality of the obtained results becomes evident from a comparison with other approaches. 相似文献
13.
《Solid State Communications》2003,125(7-8):373-376
Artificial atoms in different confinement potentials are studied using the Jensen–Feynman variational approach. The density and pair correlation function of an harmonic model with statistics are analytically calculated and used to find the variational ground state energy in two and three dimensions. The results are compared with the numerical calculations and a good correlation is found. 相似文献
14.
15.
The minimax-entropy method is compared with the known nontraditional methods of spectral estimation from a finite set of sample correlation coefficients.Nizhny Novgorod Polytechnic Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 2, pp. 220–225, February, 1994. 相似文献
16.
W.L. Smith 《Journal of Molecular Spectroscopy》2004,225(1):39-42
The use of second-order perturbation theory to derive approximate formulae for the overlap integral of two harmonic oscillator wave functions is discussed, and the results applied to the theory of intensity distributions in vibrational progressions in electronic spectra. For the vibrational progression m←0 an approximate formula is given which, when the vibrational frequencies of the initial and final states differ by less than 10%, reproduces to an accuracy of 1% or less the intensity profile calculated using the exact formulae for the overlap integrals. 相似文献
17.
18.
L. Smrčka 《Czechoslovak Journal of Physics》1984,34(7):694-704
Conclusions The developed version of the augmented plane wave method yields eigenvalues and eigenfunctions with higher accuracy than the standard LAPW, preserving its computational efficiency.The approximation of the exact radial solution by the Taylor expansion involving also the second energy derivative of the radial function, except for the first derivative, has two advantages. First, the energy dependence of the logarithmic derivatives atr=R is better described and, therefore, the method is less sensitive to the choice of the centre of expansionE
0 or, equivalently, acceptably accurate eigenvalues are obtained for the broader energy region aroundE
0. The other and probably more important advantage is that the approximate radial solutions are remarkably closer to the exact radial functions inside the muffin-tin sphere. This can be of use when evaluating the measurable quantities depending on the wave functions. 相似文献
19.
We discuss in detail the supersymmetric instanton calculus of NSVZ and extend it to chiral matter fields in the, adjoint representation. The constant Green functions induced by the instanton of supersymmetricSU (2) gauge theories are calculated systematically for the cases with and without scalar vev's bigger than the scale of the gauge theory and for nonvanishing small masses of chiral fields. Oneinstanton contributions to the Green functions containing four fields without large vevs would disturb clustering; but they are argued to vanish; two-instanton effects then lead to a pattern which quantitatively agrees with factorization and the anomaly relation. 相似文献
20.
《Physics letters. [Part B]》1986,167(3):289-294
The wave function of the universe is obtained in the form of the functional integral over lorentzian four-geometries from the path-integral quantization of the true dynamical degrees of freedom. The algorithms for quantum averages and probability amplitudes in the Wheeler-DeWitt quantum geometrodynamics are derived and the initial value problem for the wave function in superspace of three-metrics is formulated. 相似文献