arXiv subjects
Publications and source records attributed to H. C. Rosu.
A selective chronological survey of Darboux transformations as related to supersymmetric quantum mechanics, intertwining operators and inverse scattering techniques is presented. Short comments are appended to each quotation and basic concepts are explained in order to provide a useful primer
This is the English version of a friendly graduate course on Classical Mechanics, containing about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. For the Spanish version, see physics/9906066
The connection of unbroken SUSY quantum mechanics in its strictly isospectral form with the nonlinear Riccati superposition principle is pointed out
We first obtain by analogy with the continuous (differential) case the general solution of a discrete Riccati equation. Our results can be considered the discrete analog of Mielnik's construction in supersymmetric quantum mechanics [J. Math. Phys. 25, 3387 (1984)]. Moreover, we establish the full equivalence between our discrete Riccati equation and a corresponding homogeneous second order discrete linear equation. We present an application to the three-site master equation obtaining explicitly the general solutions for the simple cases of free random walk and the biased random walk
A simple, general discussion of the problem of inertia is provided both in classical physics and in the quantum world. After briefly reviewing the classical principles of equivalence (weak (WEP), Einstein (EEP), strong (SEP)), I pass to a presentation of several equivalence statements in nonrelativistic quantum mechanics and for quantum field vacuum states. It is suggested that a reasonable type of preferred quantum field vacua may be considered: those possessing stationary spectra of their vacuum fluctuations with respect to accelerated classical trajectories
We replace the usual integral in the shape function of the synchrotron spectrum by a Jackson (q-deformed) integral and write down the formulas required to calculate the Jackson first deformed form of the synchrotron shape function
We present the supersymmetric Witten and double Darboux (strictly isospectral) constructions as applied to the diffusion of thermal neutrons from an infinitely long line source. While the Witten construction is just a mathematical scheme, the double Darboux method introduces a one-parameter family of diffusion solutions which are strictly isospectral to the stationary solution. They correspond to a Darboux-transformed diffusion length which is flux dependent
We apply the strictly isospectral technique of standard supersymmetric quantum mechanics to the Q=0 factor ordered Wheeler-DeWitt equation for the Friedmann-Robertson-Walker (FRW) minisuperspace model. The resulting strictly isospectral one-parameter families of both FRW cosmological potentials and "wavefunctions of the universe" are exhibited with relevant plots
First Internet graduate course on Classical Mechanics in Spanish (Castellano). This is about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. English and Romanian versions are in (slow) progress and hopefully will be arXived. For a similar course on Quantum Mechanics, see physics/9808031
For the one-dimensional Helmholtz equation we write the corresponding time-dependent Helmholtz Hamiltonian in order to study it as an Ermakov problem and derive geometrical angles and phases in this context
In the scattering picture, thermal radiation effects may be associated with the `above barrier' reflection coefficient, which comes into play because of complex turning points. This note contains several general remarks on the application of the above statement to Schwarzschild black hole radiance
Short remarks on the problem of assigning frequency spectra to Casimir, sonoluminescence, Hawking, Unruh, and quantum optical squeezing effects are presented
If at least some Wheeler-DeWitt solutions can be interpreted as zero-energy resonances then the total s-wave cross section of the corresponding quantum universes is infinite
A simple version of the q-deformed calculus is used to generate a pair of q-nonlocal, second-order difference operators by means of deformed counterparts of Darboux intertwining operators for zero factorization energy. These deformed non-local operators may be considered as supersymmetric partners and their structure contains contributions originating in both the Hermite operator and the quantum harmonic oscillator operator. There are also extra $\pm x$ contributions. The undeformed limit, in which all q-nonlocalities wash out, corresponds to the usual supersymmetric pair of quantum mechanical harmonic oscillator Hamiltonians. The more general case of negative factorization energy is briefly discussed as well
The Schrödinger equation with attractive delta potential has been previously studied in the supersymmetric quantum mechanical approach by a number of authors, but they all used only the particular superpotential solution. Here, we introduce a one-parameter family of strictly isospectral attractive delta function potentials, which is based on the general superpotential (general Riccati) solution, we study the problem in some detail and suggest possible applications
I employ heuristically the strictly isospectral double Darboux method based on the general superpotential of unbroken nonrelativistic supersymmetry suggesting a few small steps of principle for extending its range of applications toward relativistic (gauge) physics. The application of the method to minisuperspace quantum cosmology is also briefly presented
The formal Ermakov approach for empty FRW minisuperspace cosmological models of arbitrary Hartle-Hawking factor ordering and the corresponding squeezing features are briefly discussed as a possible means of describing cosmological evolution
The strictly isospectral double Darboux method is applied to the quantum Taub model in order to generate a one-parameter family of strictly isospectral potentials for this case. The family we build is based on a scattering Wheeler-DeWitt solution first discussed by Ryan and collaborators that we slightly modified according to a suggestion due to Dunster. The strictly isospectral Taub potentials possess different (attenuated) scattering states with respect to the original Taub potential