Four dimensional Lie symmetry algebras and fourth order ordinary differential equations

Realizations of four dimensional Lie algebras as vector fields in the plane are explicitly constructed. Fourth order ordinary differential equations which admit such Lie symmetry algebras are derived. The route to their integration is described.Comment: 12 page

Análisis de la frecuencia cardiaca en el entrenamiento de gimnastas de tumbling

En el presente estudio se analiza la frecuencia cardiaca (Fc) durante el entrenamiento de gimnastas de tumbling de nivel nacional e internacional, al objeto de obtener información acerca de cómo discurre a lo largo del mismo y extrapolarlo a la planificación de los volúmenes y las intensidades de los entrenamientos. Para ello se han analizado los registros de la Fc de 8 gimnastas de edades comprendidas entre 18 y 23 años mediante la colocación de un pulsómetro Polar Sport Tester

Scattering of surface plasmon polaritons by one-dimensional inhomogeneities

The scattering of surface plasmons polaritons by a one-dimensional defect of the surface is theoretically studied, by means of both Rayleigh and modal expansions. The considered defects are either relief perturbations or variations in the permittivity of the metal. The dependence of transmission, reflection and out-of-plane scattering on parameters defining the defect is presented. We find that the radiated energy is forwardly directed (with respect to the surface plasmon propagation) in the case of an impedance defect. However, for relief defects, the radiated energy may be directed into backward or forward (or both) directions, depending on the defect width.Comment: 10 pages, 5 figures, corrected typos, some minor modifications in figures. Accepted in Phys. Rev.

A multifrequency method based on the Matched Multifilter for the detection of point sources in CMB maps

In this work we deal with the problem of simultaneous multifrequency detection of extragalactic point sources in maps of the Cosmic Microwave Background. We apply a linear filtering technique that uses spatial information and the cross-power spectrum. To make this, we simulate realistic and non-realistic flat patches of the sky at two frequencies of Planck: 44 and 100 GHz. We filter to detect and estimate the point sources and compare this technique with the monofrequency matched filter in terms of completeness, reliability, flux and spectral index accuracy. The multifrequency method outperforms the matched filter at the two frequencies and in all the studied cases in the work.Comment: 14 pages, 6 figures, 1 tabl

A New Algebraization of the Lame Equation

We develop a new way of writing the Lame Hamiltonian in Lie-algebraic form. This yields, in a natural way, an explicit formula for both the Lame polynomials and the classical non-meromorphic Lame functions in terms of Chebyshev polynomials and of a certain family of weakly orthogonal polynomialsComment: Latex2e with AMS-LaTeX and cite packages; 32 page

Culturas, políticas y prácticas de inclusión en las universidades: enfoque desde la formación inicial del profesorado

Nuestra definición de Inclusión parte de la propuesta de una educación accesible y de calidad, que contemple a todas las personas, en cualquier nivel de enseñanza. Tal definición apuesta por la construcción de una mirada crítica en el currículo y su transversalidad durante la formación de futuros profesionales, lo que consideramos fundamental para discutir la organización de una propuesta de Educación Inclusiva en el nivel de enseñanza superior. El objetivo de este proyecto es profundizar en los procesos de inclusión/exclusión educativa en la formación inicial del profesorado, ya que como futuros educadores sus concepciones al respecto influirán en su práctica docente, a lo que hay que añadir la proyección social de la figura del profesional de la educación. Este estudio incorpora, además, la consideración del tema en un ámbito internacional desde una perspectiva educativa comparada, convirtiéndolo en una experiencia mucho más enriquecedora y que aporta datos de interés para otros trabajos en el campo abordado.Our definition of inclusion originates of the proposal for an accessible and quality education, which includes everyone, at any level of education. This definition is committed to building a critical look at the curriculum and its mainstreaming in the education of future professionals; we considered the organization to discuss a proposal for Inclusive Education in the higher education level. Examine the processes of inclusion/exclusion of education in initial teacher training is the goal of this project, because as future educators their conceptions influence in their teaching practice, to which must be added the outreach they have. This study incorporates our interest in international comparative educational perspective, making it a much richer experience and it provides very interesting data

Detection/estimation of the modulus of a vector. Application to point source detection in polarization data

Given a set of images, whose pixel values can be considered as the components of a vector, it is interesting to estimate the modulus of such a vector in some localised areas corresponding to a compact signal. For instance, the detection/estimation of a polarized signal in compact sources immersed in a background is relevant in some fields like astrophysics. We develop two different techniques, one based on the Neyman-Pearson lemma, the Neyman-Pearson filter (NPF), and another based on prefiltering-before-fusion, the filtered fusion (FF), to deal with the problem of detection of the source and estimation of the polarization given two or three images corresponding to the different components of polarization (two for linear polarization, three including circular polarization). For the case of linear polarization, we have performed numerical simulations on two-dimensional patches to test these filters following two different approaches (a blind and a non-blind detection), considering extragalactic point sources immersed in cosmic microwave background (CMB) and non-stationary noise with the conditions of the 70 GHz \emph{Planck} channel. The FF outperforms the NPF, especially for low fluxes. We can detect with the FF extragalactic sources in a high noise zone with fluxes >= (0.42,0.36) Jy for (blind/non-blind) detection and in a low noise zone with fluxes >= (0.22,0.18) Jy for (blind/non-blind) detection with low errors in the estimated flux and position.Comment: 11 pages, 5 figure

Thorpe method applied to planetary boundary layer data

Turbulence affects the dynamics of atmospheric processes by enhancing the transport of mass, heat, humidity and pollutants. The global objective of our work is to analyze some direct turbulent descriptors which reflect the mixing processes in the atmospheric boundary layer (ABL). In this paper we present results related to the Thorpe displacements dT , the maximum Thorpe displacement (dT )max and the Thorpe scale LT , the Ozmidov scale and their time evolution in the ABL during a day cycle. A tethered balloon was used to obtain vertical profiles of the atmospheric physical magnitudes up to 1000m. We discuss the vertical and horizontal variability and how different descriptors are related to atmospheric mixing

Tensorial perturbations in the bulk of inflating brane worlds

In this paper we consider the stability of some inflating brane-world models in quantum cosmology. It is shown that whereas the singular model based on the construction of inflating branes from Euclidean five-dimensional anti-de Sitter space is unstable to tensorial cosmological perturbations in the bulk, the nonsingular model which uses a five-dimensional asymptotically anti-de Sitter wormhole to construct the inflating branes is stable to these perturbations.Comment: 4 pages, RevTex, to appear in Phys. Rev.