Fixed Point Theorems for Set-Valued Mappings on TVS-Cone Metric Spaces

In the context of tvs-cone metric spaces, we prove a Bishop-Phelps and a Caristi's type theorem. These results allow us to prove a fixed point theorem for $(\delta, L)$-weak contraction according to a pseudo Hausdorff metric defined by means of a cone metric

Three Photon Entanglement from Ortho-Positronium Revisited

Entanglement of three photons from the decay of ortho-positronium is re-analyzed. We use the full three body phase space to write down the entangled states classified according to the spin directions of the ortho-positronium. Even in the case when the spin is perpendicular to the decay plane, we find non-negligible phases entering the entangled state. This has not been noticed before. We advocate a fixed quantization axis of the spin for the sake of generality. A brief discussion of a three dimensional formalism for photons, including correlations, versus a two dimensional one is given.Comment: Proceedings of the second Jagiellonian Symposium on Fundamental and Applied Subatomic Physic

Guess the score, fostering collective intelligence in the class

This paper proposes the use of serious games as a tool to enhance collective intelligence of undergraduate and graduate students. The development of social skills of individuals in a group is related to the performance of the collective intelligence of the group manifested through the shared and collaborative development of intellectual tasks [1]. Guess the Score GS, is a serious game implemented by means of an online tool, created to foster the development, collaboration and engagement of students. It's has been designed with the intention of facilitating the development of individual’s social skills in a group in order to promote education of collective intelligence. This paper concludes that the design of learning activities using serious games as a support tool in education, generate awareness about of utilities of gaming in the collective learning environment and the fostering of collective intelligence education.Postprint (published version

Segregation in hard spheres mixtures under gravity. An extension of Edwards approach with two thermodynamical parameters

We study segregation patterns in a hard sphere binary model under gravity subject to sequences of taps. We discuss the appearance of the ``Brazil nut'' effect (where large particles move up) and the ``reverse Brazil nut'' effects in the stationary states reached by ``tap'' dynamics. In particular, we show that the stationary state depends only on two thermodynamical quantities: the gravitational energy of the first and of the second species and not on the sample history. To describe the properties of the system, we generalize Edwards' approach by introducing a canonical distribution characterized by two configurational temperatures, conjugate to the energies of the two species. This is supported by Monte Carlo calculations showing that the average of several quantities over the tap dynamics and over such distribution coincide. The segregation problem can then be understood as an equilibrium statistical mechanics problem with two control parameters.Comment: 7 pages, 4 figure

Glass transition in models with controlled frustration

A class of models with self-generated disorder and controlled frustration is studied. Between the trivial case, where frustration is not present at all, and the limit case, where frustration is present over every length scale, a region with local frustration is found where glassy dynamics appears. We suggest that in this region, the mean field model might undergo a p-spin like transition, and increasing the range of frustration, a crossover from a 1-step replica symmetry breaking to a continuous one might be observed.Comment: 4 pages, 6 figure

Scalar field quasinormal modes on asymptotically locally flat rotating black holes in three dimensions

The pure quadratic term of New Massive Gravity in three dimensions admits asymptotically locally flat, rotating black holes. These black holes are characterized by their mass and angular momentum, as well as by a hair of gravitational origin. As in the Myers-Perry solution in dimensions greater than five, there is no upper bound on the angular momentum. We show that, remarkably, the equation for a massless scalar field on this background can be solved in an analytic manner and that the quasinormal frequencies can be found in a closed form. The spectrum is obtained requiring ingoing boundary conditions at the horizon and an asymptotic behavior at spatial infinity that provides a well-defined action principle for the scalar probe. As the angular momentum of the black hole approaches zero, the imaginary part of the quasinormal frequencies tends to minus infinity, migrating to the north pole of the Riemann Sphere and providing infinitely damped modes of high frequency. We show that this is consistent with the fact that the static black hole within this family does not admit quasinormal modes for a massless scalar probe.Comment: 17 pages, 5 figures. V2: improved figures. V3: typos corrected, references added and title slightly changed to match the version to appear in EPJ

Measurement of CFHT Images I: Identification, Photometry and Classification

In this paper we present preliminary results from the measurement and analysis of imag es of the ecliptic zoneobtained with MegaCam at Canada-France-Hawaii Telescope (CFHT) located a t Mauna Kea(Hawaii ). We areevaluating the feasibili ty of constructing an astrometric and photometric cataloguewith all the a stronomicalsources identified on those imag es. We comm ent and discuss the criteria a nd procedures for the identificationof sources, the photometric reduction and their class ification as s tellar or extendedobjectsEn este trabajo presentamos resultados preliminares de la medición y análisis de imágenes de la zona ecliptical obtenidas con la Cámara MegaCam instalada en el Canada-France-Hawaii Telescope (CFHT) ubicado en MaunaKea(Hawaii ). Se está evaluando la posibildad de construir un catálogo astrométrico y fotométrico de las fuentes astronómicas identificadas en las mencionadas imágenes. En esta presentación se comentan y discuten los criterios empleados y procedimientos aplicados para la identificación, reducción fotométrica y clasificación de las fuentes astronómicas como estelares o extendidasFil: Calderon, Jesus Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Bustos Fierro, Iván Heriberto. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentin