Dirac quasinormal modes for a 4-dimensional Lifshitz Black Hole

We study the quasinormal modes of fermionic perturbations for an asymptotically Lifshitz black hole in 4-dimensions with dynamical exponent z=2 and plane topology for the transverse section, and we find analytically and numerically the quasinormal modes for massless fermionic fields by using the improved asymptotic iteration method and the Horowitz-Hubeny method. The quasinormal frequencies are purely imaginary and negative, which guarantees the stability of these black holes under massless fermionic field perturbations. Remarkably, both numerical methods yield consistent results; i.e., both methods converge to the exact quasinormal frequencies; however, the improved asymptotic iteration method converges in a fewer number of iterations. Also, we find analytically the quasinormal modes for massive fermionic fields for the mode with lowest angular momentum. In this case, the quasinormal frequencies are purely imaginary and negative, which guarantees the stability of these black holes under fermionic field perturbations. Moreover, we show that the lowest quasinormal frequencies have real and imaginary parts for the mode with higher angular momentum by using the improved asymptotic iteration method.Comment: Version accepted for publication in EPJC. arXiv admin note: text overlap with arXiv:1306.597

Análisis del acta de defunción del P. Rafael Landívar

El presente trabajo analiza el acta de defunción del P. Rafael Landívar sobre la base de los argumenta a persona. Del análisis se deduce que el acta es una funebris laudatio, en la que el autor ha utilizado los argumenta a persona no sólo para elogiar al poeta por medio de loci fundamentales, sino también para plasmar un epítome biográfico con la impronta de la retórica clásica.The present work analyzes Father Rafael Landívar's death certificate based on the argumenta a persona. It is deduced from the analysis that the death certificate is a funebris laudatio, where the author has used the argumenta a persona not only to price the poet by means of essential loci, but also to frame a biographic epitome that shows the cast of the classic rethoric

La historia natural en el Annus Patiens del P. Peramás : el caso de la descriptio animalium

El saber al que se han dedicado los jesuítas con más asiduidad ha sido la historia natural. Pero no siempre las noticias relacionadas con la naturaleza aparecen como tema de una única obra. A menudo, suelen estar incorporadas en relatos de viajes, cartas o diarios. En el Annus Patiens Peramás desplaza en varias ocasiones la narratio del viaje hacia el exilio para describir la pampa (ff. 28-30), las actividades jesuíticas en la Provincia del Paraguay (ff. 49-53), las misiones guaraníes (ff. 53-87), entre otras particularidades. En esta ocasión, nos detendremos en el abordaje retórico de la descripción de los animales de la pampa. Del análisis se deduce que la descriptio animalium es, desde el punto de vista retórico, una laus animalium, por medio de la cual, el jesuíta traduce el asombro frente a la novedad, da cuenta, sin clasificaciones científicas, de su relación con la naturaleza sudamericana y suma su aporte al debate epistemológico europeo sobre el continente joven.Fil: Suárez, Marcela A.. Universidad de Buenos Aire

Cancer metaphors in scientific popularization articles and their translation into Spanish

A thesis submitted in partial fulfillment of the requirements for the MA degree in English (Applied Linguistics)Capitalizing on the insights from Conceptual Metaphor Theory and a growing number of studies on the role of metaphor in the health sciences, this study explores cancer metaphors in a corpus of 6 English scientific popularization articles published by the New York Times and Scientific American and their corresponding translations into Spanish. Framed within a cognitive-discursive approach, a descriptive-contrastive methodology was applied to examine metaphor patterns used to talk about cancer and immunotherapy and explore their Spanish translations. Metaphorical expressions (MEs) in the English corpus were identified, described and quantified. In line with previous studies, Violence MEs of the prototypical warfare variety were found to be recurrently used to conceptualize the cancer-patient relationship and to explain the workings of immunotherapy. Mechanicist metaphors were also recurrent to explain the functioning of the immune system and depict cancer scientists’ actions. Other comparatively less recurrent patterns were also identified. The analysis went beyond the description of the linguistic form and considered the textual, discursive, rhetorical and cognitive functioning of metaphors. Their textual function proved to be of great importance for translation. MEs were observed to occur in chains and construct image-rich scenarios serving a rhetorical intensifying function and lending cohesion to the text. Special consideration was given to their cognitive functioning as the prevailing metaphorical frames reveal an antagonistic conceptualization of health and disease that may influence lay audiences’ thinking and acting concerning cancer. Second, the analysis concentrated on Spanish translations. Similarities and differences as to conceptual domains and local and global effects were observed. Results indicate that MEs are at times simply dropped or substituted with nonmetaphorical material. Even in cases of retention, the actual MEs chosen in Spanish are often less image-rich and less specific than the English ones. Micro level choices were examined and found to be significant for they produce different ideational and discursive effects. The overall results suggest metaphors must not be considered as an individual linguistic phenomenon as they do not occur in isolated, unconnected and sporadic form but rather in a patterned way. In order to employ MEs that bring about the same local and global effects, translators need to be aware of metaphors’ essential multifunctionality and their contribution to textual connectednessFil: Serra, Marcela A. Universidad Nacional de Córdoba. Facultad de Lenguas; Argentina

Determining the Structure of Supersymmetry-Breaking with Renormalization Group Invariants

If collider experiments demonstrate that the Minimal Supersymmetric Standard Model (MSSM) is a good description of nature at the weak scale, the experimental priority will be the precise determination of superpartner masses. These masses are governed by the weak scale values of the soft supersymmetry (SUSY)-breaking parameters, which are in turn highly dependent on the SUSY-breaking scheme present at high scales. It is therefore of great interest to find patterns in the soft parameters that can distinguish different high scale SUSY-breaking structures, identify the scale at which the breaking is communicated to the visible sector, and determine the soft breaking parameters at that scale. In this work, we demonstrate that 1-loop Renormalization Group~(RG) invariant quantities present in the MSSM may be used to answer each of these questions. We apply our method first to generic flavor-blind models of SUSY-breaking, and then examine in detail the subset of these models described by General Gauge Mediation and the constrained MSSM with non-universal Higgs masses. As RG invariance generally does not hold beyond leading-log order, we investigate the magnitude and direction of the 2-loop corrections. We find that with superpartners at the TeV scale, these 2-loop effects are either negligible, or they are of the order of optimistic experimental uncertainties and have definite signs, which allows them to be easily accounted for in the overall uncertainty.Comment: v2 -- references added, version to be published in PRD; 40 page