arXiv subjects
Publications and source records attributed to H. C. Rosu.
We study the power spectrum of a class of noise effects generated by means of a digital-like disorder in the traveling variable of the conjectured Ginzburg-Landau-Montroll kink excitations moving along the walls of the microtubules. We have found a 1/f^α noise with α\in (1.82-2.04) on all the time scales we have considered
The simple supersymmetric approach recently used by Dutt, Gangopadhyaya, and Sukhatme [Am. J. Phys. 65 400 (1997)] for spherical harmonics is generalized to Jacobi equation, including also the intermediate Gegenbauer case
We connect the classical free damping cases by means of Rosner's construction in supersymmetric quantum mechanics. Starting with the critical damping, one can obtain in the underdamping case a chirping of instantaneous physical frequency ω^{2}(t) \propto ω_{u}^{2}sech^2(ω_{u}t), whereas in the overdamped case the "chirping" is of the (unphysical) type ω^{2}(t)\proptoω_{o}^{2}sec^{2}(ω_{o}t), where ω_{u}$ and $ω_{o} are the underdamped and overdamped frequency parameters, respectively
We determine the class of damped modes \tilde{y} which are related to the common free damping modes y by supersymmetry. They are obtained by employing the factorization of Newton's differential equation of motion for the free damped oscillator by means of the general solution of the corresponding Riccati equation together with Witten's method of constructing the supersymmetric partner operator. This procedure leads to one-parameter families of (transient) modes for each of the three types of free damping, corresponding to a particular type of %time-dependent angular frequency. %time-dependent, antirestoring acceleration (adding up to the usual Hooke restoring acceleration) of the form a(t)=\frac{2γ^2}{(γt+1)^{2}}\tilde{y}, where γis the family parameter that has been chosen as the inverse of the Riccati integration constant. In supersymmetric terms, they represent all those one Riccati parameter damping modes having the same Newtonian free damping partner mode
We briefly tackle the following concepts in the Demkov-Ostrovsky (DO) nodeless sector: (i) orbital impedance, (ii) orbital capacity, (iii) closeness to reflectionlessness. Moreover, using previous supersymmetric results for the DO problem, a strictly isospectral effect in the DO orbital impedances is discussed and explicit plots are displayed for the Maxwell fisheye lens. This effect, though rather small, is general, that is, it may apply to any focusing structure.
This is a short note on the black hole remote-sensing problem, i.e., finding out `surface' temperature distributions of various types of small (micron-sized) black holes from the spectral measurements of their Hawking grey pulses. Chen's modified Moebius inverse transform is illustrated in this context
We briefly present the supersymmetric double Darboux method and next apply it to the continuum of the quantum Taub cosmological model as a toy model in order to generate a one-parameter family of bosonic Taub potentials and the corresponding wavefunctions
We show that closed, radiation-filled Friedmann-Robertson-Walker quantum universes of arbitrary factor ordering obey the Whittaker equation. We also present the formal Witten factorization as well as the double Darboux strictly isospectral scheme for the Whittaker equation
Fisher's arrow of `time' in a cosmological phase space defined as in quantum optics (i.e., whose points are coherent states) is introduced as follows. Assuming that the phase space evolution of the universe starts from an initial squeezed cosmological state towards a final thermal one, a Fokker-Planck equation for the time-dependent, cosmological Q phase space probability distribution can be written down. Next, using some recent results in the literature, we derive an information arrow of time for the Fisher phase space cosmological entropy based on the Q function. We also mention the application of Fisher's arrow of time to stochastic inflation models
I present the factorization(s) of the Wheeler-DeWitt equation for vacuum FRW minisuperspace universes of arbitrary Hartle-Hawking factor ordering, including the so-called strictly isospectral supersymmetric method. By the latter means, one can introduce an infinite class of singular FRW minisuperspace wavefunctions characterized by a Darboux parameter that mathematically speaking is a Riccati integration constant, while physically determines the position of these strictly isospectral singularities on the Misner time axis
We present a supersymmetric analysis of the wave problem with a Demkov-Ostrovsky spherically symmetric class of focusing potentials at zero energy. Following a suggestion of Lévai, we work in the so-called R_0=0 sector in order to obtain the superpartner (fermionic) potentials within Witten's supersymmetric procedure. General solutions of the superpotential for the known physical cases are given explicitly.
I discuss a phenomenological model of the nucleon in which a small anti-de Sitter bag is placed into the Skyrmion configuration. Such a bag has a timelike boundary and allows naturally the Cheshire Cat Principle. Very important in this model is the membrane of the bag, the 3-dimensional time-space manifold S^{1}\times S^{2}, in which topological techniques will come into play
The bosonic strictly isospectral problem for Demkov-Ostrovsky (DO) effective potentials in the radially nodeless sector is first solved in the supersymmetric Darboux-Witten (DW) half line (or l-changing) procedure. As an application, for the κ=1 class, if one goes back to optics examples, it might be possible to think of a one-parameter family of Maxwell lenses having the same optical scattering properties in the nodeless radial sector. Although the relative changes in the index of refraction that one may introduce in this way are at the level of several percents, at most, for all DO orbital quantum numbers l\geq 0, the index profiles are different from the original Maxwell one, possessing an inflection point within the lens. I pass then to the DW full line (or N-changing) procedure, obtaining the corresponding Morse-type problem for which the supersymmetric results are well established, and finally come back to the half line with well-defined results
I comment on a number of theoretical issues related to magnetobremsstrahlung, and especially on synchrotron radiation and Unruh (temperature) radiation, that I consider of importance for the current progress towards a better understanding of the stationary features of such fundamental radiation patterns both in an accelerator context and, more generally, in the physical world
If the dynamic instability of microtubules follows a gamma distribution then one can associate to it a Cantor set
A picture of the Planck scale universe as a network of mesoscopic (with respect to that scale) resonators connected through quasi-one-dimensional waveguides is presented
We discuss the proposal of Bell and Leinaas (BL) to measure the circular Unruh effect in storage rings. The ideal concept `circular Unruh effect' has a more realistic correspondent such as `circular vacuum noise' used by Shin Takagi [Prog. Theor. Phys. Suppl. 88, 1 (1986)] The BL resonance behavior does not fit to the SPEAR first order betatron resonance at 3.605 GeV, but of course, the real experimental situation is much more complicated, corresponding, as a matter of fact, to an even more general term that one may call `synchrotron noise'. In the final section we focus on radiometric aspects of storage ring physics, such as the problem of establishing better quantum field radiometric standards at high energies. The Unruh-like effect could be a useful guide for that purpose