7,159 research outputs found
A Family of Quasi-solvable Quantum Many-body Systems
We construct a family of quasi-solvable quantum many-body systems by an
algebraic method. The models contain up to two-body interactions and have
permutation symmetry. We classify these models under the consideration of
invariance property. It turns out that this family includes the rational,
hyperbolic (trigonometric) and elliptic Inozemtsev models as the particular
cases.Comment: 9 pages, REVTeX4, final versio
Quasi-exact solvability beyond the SL(2) algebraization
We present evidence to suggest that the study of one dimensional
quasi-exactly solvable (QES) models in quantum mechanics should be extended
beyond the usual \sla(2) approach. The motivation is twofold: We first show
that certain quasi-exactly solvable potentials constructed with the \sla(2)
Lie algebraic method allow for a new larger portion of the spectrum to be
obtained algebraically. This is done via another algebraization in which the
algebraic hamiltonian cannot be expressed as a polynomial in the generators of
\sla(2). We then show an example of a new quasi-exactly solvable potential
which cannot be obtained within the Lie-algebraic approach.Comment: Submitted to the proceedings of the 2005 Dubna workshop on
superintegrabilit
Nonlinear Pseudo-Supersymmetry in the Framework of N-fold Supersymmetry
We recall the importance of recognizing the different mathematical nature of
various concepts relating to PT-symmetric quantum theories. After clarifying
the relation between supersymmetry and pseudo-supersymmetry, we prove
generically that nonlinear pseudo-supersymmetry, recently proposed by Sinha and
Roy, is just a special case of N-fold supersymmetry. In particular, we show
that all the models constructed by these authors have type A 2-fold
supersymmetry. Furthermore, we prove that an arbitrary one-body quantum
Hamiltonian which admits two (local) solutions in closed form belongs to type A
2-fold supersymmetry, irrespective of whether or not it is Hermitian,
PT-symmetric, pseudo-Hermitian, and so on.Comment: 10 pages, no figures; typos correcte
The classroom of Physical Education and students with disabilities
Este estudio versa sobre el proceso de construcción y validación de un instrumento estandarizado cuyo objetivo ha sido analizar la realidad educativa de los docentes de Educación Física en la etapa de primaria ante alumnado con discapacidad motora y derivar del mismo los elementos clave que justifiquen la construcción de un plan de formación permanente del profesorado en este ámbito. El proceso llevado a cabo paso por llevar a cabo en primer lugar un juicio de expertos y expertas para posteriormente someter el borrador de aquí derivado a un pilotaje con un total de 57 docentes de Córdoba. El cuestionario definitivo goza de las suficientes garantías para ser aplicado, analizado e interpretado y ha permitido extraer como dimensiones formativas las siguientes: didáctica de la Educación Física, herramientas didáctico educativas, estrategias de trabajo en el aula, habilidades para el ejercicio de la docentes y recursos tecnológicos
Ejercicio físico y radicales libres, ¿es necesaria una suplementación con antioxidantes?
Silent speech: restoring the power of speech to people whose larynx has been removed
Every year, some 17,500 people in Europe and North America lose the power of speech after undergoing a laryngectomy, normally as a treatment for throat cancer. Several research groups have recently demonstrated that it is possible to restore speech to these people by using machine learning to learn the transformation from articulator movement to sound. In our project articulator movement is captured by a technique developed by our collaborators at Hull University called Permanent Magnet Articulography (PMA), which senses the changes of magnetic field caused by movements of small magnets attached to the lips and tongue. This solution, however, requires synchronous PMA-and-audio recordings for learning the transformation and, hence, it cannot be applied to people who have already lost their voice. Here we propose to investigate a variant of this technique in which the PMA data are used to drive an articulatory synthesiser, which generates speech acoustics by simulating the airflow through a computational model of the vocal tract. The project goals, participants, current status, and achievements of the project are discussed below.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Statistical measure of complexity for quantum systems with continuous variables
The Fisher-Shannon statistical measure of complexity is analyzed for a
continuous manifold of quantum observables. It is probed then than calculating
it only in the configuration and momentum spaces will not give a complete
description for certain systems. Then a more general measure for the complexity
of a quantum system by the integration of the usual Fisher-Shannon measure over
all the parameter space is proposed. Finally, these measures are applied to the
concrete case of a free particle in a box.Comment: 6 pages, 5 figures. Published versio
Confinement of electrons in layered metals
We analyze the out of plane hopping in models of layered systems where the
in--plane properties deviate from Landau's theory of a Fermi liquid. We show
that the hopping term acquires a non trivial energy dependence, due to the
coupling to in plane excitations, and can be either relevant or irrelevant at
low energies or temperatures. The latter is always the case if the Fermi level
lies close to a saddle point in the dispersion relation.Comment: 4 pages, 1 eps figur
- …