112 research outputs found
Radial Coulomb and Oscillator Systems in Arbitrary Dimensions
A mapping is obtained relating analytical radial Coulomb systems in any
dimension greater than one to analytical radial oscillators in any dimension.
This mapping, involving supersymmetry-based quantum-defect theory, is possible
for dimensions unavailable to conventional mappings. Among the special cases is
an injection from bound states of the three-dimensional radial Coulomb system
into a three-dimensional radial isotropic oscillator where one of the two
systems has an analytical quantum defect. The issue of mapping the continuum
states is briefly considered.Comment: accepted for publication in J. Math. Phy
Singular solutions to the Seiberg-Witten and Freund equations on flat space from an iterative method
Although it is well known that the Seiberg-Witten equations do not admit
nontrivial solutions in flat space, singular solutions to them have been
previously exhibited -- either in or in the dimensionally reduced spaces
and -- which have physical interest. In this work, we employ an
extension of the Hopf fibration to obtain an iterative procedure to generate
particular singular solutions to the Seiberg-Witten and Freund equations on
flat space. Examples of solutions obtained by such method are presented and
briefly discussed.Comment: 7 pages, minor changes. To appear in J. Math. Phy
Unified treatment of the Coulomb and harmonic oscillator potentials in dimensions
Quantum mechanical models and practical calculations often rely on some
exactly solvable models like the Coulomb and the harmonic oscillator
potentials. The dimensional generalized Coulomb potential contains these
potentials as limiting cases, thus it establishes a continuous link between the
Coulomb and harmonic oscillator potentials in various dimensions. We present
results which are necessary for the utilization of this potential as a model
and practical reference problem for quantum mechanical calculations. We define
a Hilbert space basis, the generalized Coulomb-Sturmian basis, and calculate
the Green's operator on this basis and also present an SU(1,1) algebra
associated with it. We formulate the problem for the one-dimensional case too,
and point out that the complications arising due to the singularity of the
one-dimensional Coulomb problem can be avoided with the use of the generalized
Coulomb potential.Comment: 18 pages, 3 ps figures, revte
An Invertible Linearization Map for the Quartic Oscillator
The set of world lines for the non-relativistic quartic oscillator satisfying
Newton's equation of motion for all space and time in 1-1 dimensions with no
constraints other than the "spring" restoring force is shown to be equivalent
(1-1-onto) to the corresponding set for the harmonic oscillator. This is
established via an energy preserving invertible linearization map which
consists of an explicit nonlinear algebraic deformation of coordinates and a
nonlinear deformation of time coordinates involving a quadrature. In the
context stated, the map also explicitly solves Newton's equation for the
quartic oscillator for arbitrary initial data on the real line. This map is
extended to all attractive potentials given by even powers of the space
coordinate. It thus provides classes of new solutions to the initial value
problem for all these potentials
Multiple electron trapping in the fragmentation of strongly driven molecules
We present a theoretical quasiclassical study of the formation, during
Coulomb explosion, of two highly excited neutral H atoms (double H) of
strongly driven H. In this process, after the laser field is turned off
each electron occupies a Rydberg state of an H atom. We show that two-electron
effects are important in order to correctly account for double H
formation. We find that the route to forming two H atoms is similar to
pathway B that was identified in Phys. Rev. A {\bf 85} 011402 (R) as one of the
two routes leading to single H formation. However, instead of one
ionization step being "frustrated" as is the case for pathway B, both
ionization steps are "frustrated" in double H formation. Moreover, we
compute the screened nuclear charge that drives the explosion of the nuclei
during double H formation.Comment: 4 pages, 6 figure
Coulomb-oscillator duality in spaces of constant curvature
In this paper we construct generalizations to spheres of the well known
Levi-Civita, Kustaanheimo-Steifel and Hurwitz regularizing transformations in
Euclidean spaces of dimensions 2, 3 and 5. The corresponding classical and
quantum mechanical analogues of the Kepler-Coulomb problem on these spheres are
discussed.Comment: 33 pages, LaTeX fil
N-Body Growth of a Bahcall-Wolf Cusp Around a Black Hole
We present a clear N-body realization of the growth of a Bahcall-Wolf f ~
E^0.25 (rho ~ 1/r^1.75) density cusp around a massive object ("black hole") at
the center of a stellar system. Our N-body algorithm incorporates a novel
implementation of Mikkola-Aarseth chain regularization to handle close
interactions between star and black hole particles. Forces outside the chain
were integrated on a GRAPE-6A/8 special-purpose computer with particle numbers
up to N=0.25 x 10^6. We compare our N-body results with predictions of the
isotropic Fokker-Planck equation and verify that the time dependence of the
density (both configuration and phase-space) predicted by the Fokker-Planck
equation is well reproduced by the N-body algorithm, for various choices of N
and of the black hole mass. Our results demonstrate the feasibility of
direct-force integration techniques for simulating the evolution of galactic
nuclei on relaxation time scales.Comment: 4 pages, 3 figure
How to relate the oscillator and Coulomb systems on spheres and pseudospheres?
We show that the oscillators on a sphere and pseudosphere are related, by the
so-called Bohlin transformation, with the Coulomb systems on the pseudosphere:
the even states of an oscillator yields the conventional Coulomb system on
pseudosphere, while the odd states yield the Coulomb system on pseudosphere in
the presence of magnetic flux tube generating half spin. In the higher
dimensions the oscillator and Coulomb(-like) systems are connected in the
similar way. In particular, applying the Kustaanheimo-Stiefel transformation to
the oscillators on sphere and pseudosphere, we obtained the preudospherical
generalization of MIC-Kepler problem describing three-dimensional charge-dyon
system.Comment: 12 pages, Based on talk given at XXIII Colloquium on Group
Theoretical Methods in Physics (July 31-August 5, 2000, Dubna
Autoparallels From a New Action Principle
We present a simpler and more powerful version of the recently-discovered
action principle for the motion of a spinless point particle in spacetimes with
curvature and torsion. The surprising feature of the new principle is that an
action involving only the metric can produce an equation of motion with a
torsion force, thus changing geodesics to autoparallels. This additional
torsion force arises from a noncommutativity of variations with parameter
derivatives of the paths due to the closure failure of parallelograms in the
presence of torsionComment: Paper in src. Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Read paper directly
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http://www.physik.fu-berlin.de/~kleinert/kleiner_re243/preprint.htm
Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization via periodic orbits
A hierarchical ordering is demonstrated for the periodic orbits in a strongly
coupled multidimensional Hamiltonian system, namely the hydrogen atom in
crossed electric and magnetic fields. It mirrors the hierarchy of broken
resonant tori and thereby allows one to characterize the periodic orbits by a
set of winding numbers. With this knowledge, we construct the action variables
as functions of the frequency ratios and carry out a semiclassical torus
quantization. The semiclassical energy levels thus obtained agree well with
exact quantum calculations
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