9,199 research outputs found

    Aprendizaje basado en problemas (abp) y didáctica del juego como estrategias de motivación pedagógica, en el área de ciencias sociales

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    Considerando que el propósito de este trabajo es mostrar que a través de la aplicación de las estrategias como el APB y la Didáctica del juego aplicado a los alumnos de Bachillerato en el área de las Ciencias Sociales, obtuve una reconceptualización de mi práctica docente, logrando con ello cambios significativos que se originaron de la aplicación de dichas estrategias.Este trabajo de investigación está basado en la metodología de la investigación-acción y en el enfoque constructivista, que como señala Barrerà (2000), la idea básica de este enfoque, es de aprender y enseñar, lejos de ser meros procesos de repetición y acumulación de conocimientos, implican transformar la mente de quien aprende, que debe reconstruir a nivel personal los productos y procesos culturales con el fin de apropiarse de ellos. En él se presenta el proceso y los resultados obtenidos de mi experiencia docente

    Asymptotic symmetries of three dimensional gravity and the membrane paradigm

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    The asymptotic symmetry group of three-dimensional (anti) de Sitter space is the two dimensional conformal group with central charge c=3/2Gc=3\ell/2G. Usually the asymptotic charge algebra is derived using the symplectic structure of the bulk Einstein equations. Here, we derive the asymptotic charge algebra by a different route. First, we formulate the dynamics of the boundary as a 1+1-dimensional dynamical system. Then we realize the boundary equations of motion as a Hamiltonian system on the dual Lie algebra, g\mathfrak{g}^*, of the two-dimensional conformal group. Finally, we use the Lie-Poisson bracket on g\mathfrak{g}^* to compute the asymptotic charge algebra. This streamlines the derivation of the asymptotic charge algebra because the Lie-Poisson bracket on the boundary is significantly simpler than the symplectic structure derived from the bulk Einstein equations. It also clarifies the analogy between the infinite dimensional symmetries of gravity and fluid dynamics.Comment: 15 page

    The classical double copy in maximally symmetric spacetimes

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    The classical double copy procedure relates classical asymptotically-flat gravitational field solutions to Yang-Mills and scalar field solutions living in Minkowski space. In this paper we extend this correspondence to maximally symmetric curved spacetimes. We consider asymptotically (A)dS spacetimes in Kerr-Schild form and construct the corresponding single and zeroth copies. In order to clarify the interpretation of these copies, we study several examples including (A)dS-Schwarzschild, (A)dS-Kerr, black strings, black branes, and waves, paying particular attention to the source terms. We find that the single and zeroth copies of stationary solutions satisfy different equations than those of wave solutions. We also consider how to obtain Einstein-Maxwell solutions using this procedure. Finally, we derive the classical single and zeroth copy of the BTZ black hole.Comment: matches published versio

    Radiation of scalar modes and the classical double copy

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    The double copy procedure relates gauge and gravity theories through color-kinematics replacements and holds for both scattering amplitudes and in classical contexts. Moreover, it has been shown that there is a web of theories whose scattering amplitudes are related through operations that exchange color and kinematic factors. In this paper, we generalize and extend this procedure by showing that the classical perturbative double copy of pions corresponds to special Galileons. We consider point-particles coupled to the relevant scalar fields, and find the leading and next to leading order radiation amplitudes. By considering couplings motivated by those that would arise from extracting the longitudinal modes of the gauge and gravity theories, we are able to map the non-linear sigma model radiation to that of the special Galileon. We also construct the single copy by mapping the bi-adjoint scalar radiation to the non-linear sigma model radiation through generalized color-kinematics replacements.Comment: 30 pages, 5 figure

    Testing Hybrid Natural Inflation with BICEP2

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    We analyse Hybrid Natural Inflation in view of the recent results for the tensor index reported by BICEP2. We find that it predicts a large running of the scalar spectrum which is potentially detectable by large scale structure and 21cm21\, \mathrm{cm} observations. The running of the running is also relatively large becoming close to 10210^{-2}. Along the way, we find general consistency relations at which observables are subject if the slow-roll approximation is imposed. Failure to satisfy these equations by the values obtained for the observables in surveys would be a failure of the slow-roll approximation itself.Comment: V3: Published versio
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