655 research outputs found
Alternative Solution of the Path Integral for the Radial Coulomb Problem
In this Letter I present an alternative solution of the path integral for the
radial Coulomb problem which is based on a two-dimensional singular version of
the Levi-Civita transformation.Comment: 7 pages, Late
Path Integral Approach for Spaces of Non-constant Curvature in Three Dimensions
In this contribution I show that it is possible to construct
three-dimensional spaces of non-constant curvature, i.e. three-dimensional
Darboux-spaces. Two-dimensional Darboux spaces have been introduced by Kalnins
et al., with a path integral approach by the present author. In comparison to
two dimensions, in three dimensions it is necessary to add a curvature term in
the Lagrangian in order that the quantum motion can be properly defined. Once
this is done, it turns out that in the two three-dimensional Darboux spaces,
which are discussed in this paper, the quantum motion is similar to the
two-dimensional case. In \threedDI we find seven coordinate systems which
separate the Schr\"odinger equation. For the second space, \threedDII, all
coordinate systems of flat three-dimensional Euclidean space which separate the
Schr\"odinger equation also separate the Schr\"odinger equation in
\threedDII. I solve the path integral on \threedDI in the -system,
and on \threedDII in the -system and in spherical coordinates
On the Path Integral in Imaginary Lobachevsky Space
The path integral on the single-sheeted hyperboloid, i.e.\ in -dimensional
imaginary Lobachevsky space, is evaluated. A potential problem which we call
``Kepler-problem'', and the case of a constant magnetic field are also
discussed.Comment: 16 pages, LATEX, DESY 93-14
On the Green function of linear evolution equations for a region with a boundary
We derive a closed-form expression for the Green function of linear evolution
equations with the Dirichlet boundary condition for an arbitrary region, based
on the singular perturbation approach to boundary problems.Comment: 9 page
Path Integral Approach for Superintegrable Potentials on Spaces of Non-constant Curvature: II. Darboux Spaces DIII and DIV
This is the second paper on the path integral approach of superintegrable
systems on Darboux spaces, spaces of non-constant curvature. We analyze in the
spaces \DIII and \DIV five respectively four superintegrable potentials,
which were first given by Kalnins et al. We are able to evaluate the path
integral in most of the separating coordinate systems, leading to expressions
for the Green functions, the discrete and continuous wave-functions, and the
discrete energy-spectra. In some cases, however, the discrete spectrum cannot
be stated explicitly, because it is determined by a higher order polynomial
equation.
We show that also the free motion in Darboux space of type III can contain
bound states, provided the boundary conditions are appropriate. We state the
energy spectrum and the wave-functions, respectively
Classification of quantum superintegrable systems with quadratic integrals on two dimensional manifolds
There are two classes of quantum integrable systems on a manifold with
quadratic integrals, the Liouville and the Lie integrable systems as it happens
in the classical case. The quantum Liouville quadratic integrable systems are
defined on a Liouville manifold and the Schr\"odinger equation can be solved by
separation of variables in one coordinate system. The Lie integrable systems
are defined on a Lie manifold and are not generally separable ones but the can
be solved. Therefore there are superintegrable systems with two quadratic
integrals of motion not necessarily separable in two coordinate systems. The
quantum analogues of the two dimensional superintegrable systems with quadratic
integrals of motion on a manifold are classified by using the quadratic
associative algebra of the integrals of motion. There are six general
fundamental classes of quantum superintegrable systems corresponding to the
classical ones. Analytic formulas for the involved integrals are calculated in
all the cases. All the known quantum superintegrable systems are classified as
special cases of these six general classes. The coefficients of the associative
algebra of the general cases are calculated. These coefficients are the same as
the coefficients of the classical case multiplied by plus quantum
corrections of order and .Comment: LaTeX file, 25 page
Magnetic Transition in the Kondo Lattice System CeRhSn2
Our resistivity, magnetoresistance, magnetization and specific heat data
provide unambiguous evidence that CeRhSn2 is a Kondo lattice system which
undergoes magnetic transition below 4 K.Comment: 3 pages text and 5 figure
Multi-Channel Electron Transfer Reactions: An Analytically Solvable Model
We propose an analytical method for understanding the problem of
multi-channel electron transfer reaction in solution, modeled by a particle
undergoing diffusive motion under the influence of one donor and several
acceptor potentials. The coupling between the donor potential and acceptor
potentials are assumed to be represented by Dirac Delta functions. The
diffusive motion in this paper is represented by the Smoluchowski equation. Our
solution requires the knowledge of the Laplace transform of the Green's
function for the motion in all the uncoupled potentials.Comment: arXiv admin note: substantial text overlap with arXiv:0903.306
Proper incorporation of self-adjoint extension method to Green's function formalism : one-dimensional -function potential case
One-dimensional -function potential is discussed in the framework
of Green's function formalism without invoking perturbation expansion. It is
shown that the energy-dependent Green's function for this case is crucially
dependent on the boundary conditions which are provided by self-adjoint
extension method. The most general Green's function which contains four real
self-adjoint extension parameters is constructed. Also the relation between the
bare coupling constant and self-adjoint extension parameter is derived.Comment: LATEX, 13 page
The Coulomb-Oscillator Relation on n-Dimensional Spheres and Hyperboloids
In this paper we establish a relation between Coulomb and oscillator systems
on -dimensional spheres and hyperboloids for . We show that, as in
Euclidean space, the quasiradial equation for the dimensional Coulomb
problem coincides with the -dimensional quasiradial oscillator equation on
spheres and hyperboloids. Using the solution of the Schr\"odinger equation for
the oscillator system, we construct the energy spectrum and wave functions for
the Coulomb problem.Comment: 15 pages, LaTe
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