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M. Kibler

Publications and source records attributed to M. Kibler.

35 records · Page 2Linked to original sources

The k-fermions as objects interpolating between fermions and bosons

Operators, refered to as k-fermion operators, that interpolate between boson and fermion operators are introduced through the consideration of two noncommuting quon algebras. The deformation parameters for these quon algebras are roots of unity connected to an integer k. The case k=2 corresponds to fermions and the limiting case k going to infinity to bosons. Generalized coherent states and supercoherent states are investigated. The Dirac quantum phase operator and the Fairlie-Fletcher-Zachos algebra are also considered.

quant-ph↗

On a Generalized Oscillator System: Interbasis Expansions

This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The problem of interbasis expansions of the wavefunctions is completely solved. A connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) is discussed.

quant-ph↗

Application of a Two-Parameter Quantum Algebra to Rotational Spectroscopy of Nuclei

A two-parameter quantum algebra $U_{qp}({\rm u}_2)$ is briefly investigated in this paper. The basic ingredients of a model based on the $U_{qp}({\rm u}_2)$ symmetry, the $qp$-rotator model, are presented in detail. Some general tendencies arising from the application of this model to the description of rotational bands of various atomic nuclei are summarized.

nucl-th↗

Statistical Mechanics of $qp$-Bosons in $D$ Dimensions

This paper is concerned with statistical properties of a gas of $qp$-bosons without interaction. Some thermodynamical functions for such a system in $D$ dimensions are derived. Bose-Einstein condensation is discussed in terms of the parameters $q$ and $p$. Finally, the second-order correlation function of a gas of photons is calculated.

quant-ph↗

Coulomb Energy Averaged over the $n\ell^N$-Atomic States with a Definite Spin

A purely group-theoretical approach (for which the symmetric group plays a central rôle), based upon the use of properties of fractional-parentage coefficients and isoscalar factors, is developed for the derivation of the Coulomb energy averaged over the states, with a definite spin, arising from an atomic configuration $n \ell^N$.

atom-ph↗

The Periodic Table in Flatland

The $D$-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in $D$ dimensions. This rule together with an {\it Aufbau Prinzip} is applied to produce a $D$-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the $q$-deformed algebra $U_q($so$(D))$, that breaks down the SO($D+1$) dynamical symmetry of the hydrogen atom in $D$ dimensions. The $D=2$ case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values $q=0.8$ and $q=1$, respectively, of the deformation parameter $q$.

atom-ph↗

Two-Photon Spectroscopy Between States of Opposite Parities

Magnetic- and electric-dipole two-photon absorption (MED-TPA), recently introduced as a new spectroscopic technique for studying transitions between states of opposite parities, is investigated from a theoretical point of view. A new approximation, referred to as {\it weak quasi-closure approximation}, is used together with symmetry adaptation techniques to calculate the transition amplitude between states having well-defined symmetry properties. Selection rules for MED-TPA are derived and compared to selection rules for parity-forbidden electric-dipole two-photon absorption (ED-TPA).

atom-ph↗

An $U_{qp}(u_2)$ Rotor Model for Rotational Bands of Superdeformed Nuclei

A nonrigid rotor model is developed from the two-parameter quantum algebra $U_{qp}({\rm u}_2)$. [This model presents the $U_{qp}({\rm u}_2)$ symmetry and shall be referred to as the qp-rotor model.] A rotational energy formula as well as a qp-deformation of E2 reduced transition probabilities are derived. The qp-rotor model is applied (through fitting procedures) to twenty rotational bands of superdeformed nuclei in the $A \sim 130$, 150 and 190 mass regions. Systematic comparisons between the qp-rotor model and the q-rotor model of Raychev, Roussev and Smirnov, on one hand, and a basic three-parameter model, on the other hand, are performed on energy spectra, on dynamical moments of inertia and on B(E2) values. The physical signification of the deformation parameters q and p is discussed.

nucl-th↗

Application of Non-Bijective Transformations to Various Potentials

Some results about non-bijective quadratic transformations generalizing the Kustaanheimo-Stiefel and the Levi-Civita transformations are reviewed in §1. The three remaining sections are devoted to new results: §2 deals with the Lie algebras under constraints associated to some Hurwitz transformations; §3 and §4 are concerned with several applications of some Hurwitz transformations to wave equations for various potentials in $R^3$ and $R^5$.

hep-th↗

On Hurwitz Transformations

A bibliography on the Hurwitz transformations is given. We deal here, with some details, with two particular Hurwitz transformations, viz, the $\grq \to \grt$ Kustaanheimo-Stiefel transformation and its $\grh \to \grc$ compact extension. These transformations are derived in the context of Fock-Bargmann-Schwinger calculus with special emphasis on angular momentum theory.

hep-th↗

On a Generalized Kepler-Coulomb System: Interbasis Expansions

This paper deals with a dynamical system that generalizes the Kepler-Coulomb system and the Hartmann system. It is shown that the Schrödinger equation for this generalized Kepler-Coulomb system can be separated in prolate spheroidal coordinates. The coefficients of the interbasis expansions between three bases (spherical, parabolic and spheroidal) are studied in detail. It is found that the coefficients for the expansion of the parabolic basis in terms of the spherical basis, and vice-versa, can be expressed through the Clebsch-Gordan coefficients for the group SU(2) analytically continued to real values of their arguments. The coefficients for the expansions of the spheroidal basis in terms of the spherical and parabolic bases are proved to satisfy three-term recursion relations.

hep-th↗

Two-Parametric Quantum-Deformed Dual Amplitude

From a 2-parametric deformation of the harmonic oscillator algebra we construct a 4-point dual amplitude with nonlinear trajectories. The earlier versions of the q-deformed dual models are reproduced as limiting cases of the present model.

hep-th↗

An Uqp(u2) Model for Rotational Bands of Nuclei

A rotational model is developed from a new version of the two-parameter quantum algebra $U_{qp}({\rm u}_2)$. This model is applied to the description of some recent experimental data for the rotating superdeformed nuclei $^{192-194-196-198}{\rm Pb}$ and $^{192-194 }{\rm Hg}$. A comparison between the $U_{qp}({\rm u}_2)$ model presented here and the Raychev-Roussev-Smirnov model with $U_{q }({\rm su}_2)$ symmetry shows the relevance of the introduction of a second parameter of a ``quantum algebra'' type.

hep-th↗