Constrained Differential Renormalization of Yang-Mills Theories

We renormalize QCD to one loop in coordinate space using constrained differential renormalization, and show explicitly that the Slavnov-Taylor identities are preserved by this method.Comment: LaTex, 13 pages with 2 ps figure

Electroweak Precision Observables and the Unhiggs

We compute one-loop corrections to the S and T parameters in the Unhiggs scenario. In that scenario, the Standard Model Higgs is replaced by a non-local object, called the Unhiggs, whose spectral function displays a continuum above the mass gap. The Unhiggs propagator has effectively the same UV properties as the Standard Model Higgs propagator, which implies that loop corrections to the electroweak precision observables are finite and calculable. We show that the Unhiggs is consistent with electroweak precision tests when its mass gap is at the weak scale; in fact, it then mimics a light SM Higgs boson. We also argue that the Unhiggs, while being perfectly visible to electroweak precision observables, is invisible to detection at LEP.Comment: 13 pages; v2: references added, discussion of production cross-section expande

"The Encyclopedia of Post-Colonial Literatures in English" : teoría, análisis como obra de documentación y crítica

Este trabajo se ha centrado en el análisis de The Ecyclopedia of Post-colonial Literatures in English para poder valorar su relevancia en la labor del traductor en cuanto a obra de documentación para literatura poscolonial del inglés. Antes de abordar el análisis, abordamos el poscolonialismo como época y su relación con los estudios poscoloniales, y por tanto, con la Traductología, para así poder entender las diferencias que existen entre la producción literaria poscolonial y el resto de literatura. Para poder saber si los traductores verían la enciclopedia como una fuente de documentación útil, llevamos a cabo una investigación empírica basada en hipótesis tales como que los alumnos no conocen esta enciclopedia, que de conocerla la valorarían muy positivamente o que no son conscientes de hasta qué punto en el futuro se podrían encontrar con un encargo de traducción de un autor de antiguas colonias, y por tanto, con la necesidad de indagar sobre la literatura poscolonial y los estudios poscoloniales. De este modo, este trabajo cuenta con tres partes diferenciadas pero conectadas entra sí: un apartado destinado a la base teórica sobre el poscolonialismo y los estudios poscoloniales; el análisis de la enciclopedia desde el punto de vista de un usuario y, por último, la realización de una investigación empírica sobre el conocimiento que tienen los alumnos de la obra y cómo valoran su aportación como herramienta documental

Imagen dialéctica y cuerpo en escena Hacia una nueva comprensión de la fi delidad al pasado

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Entre el pasado y su transmisión. Estéticas de la dialéctica inmóvil.

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Sacudirse el pasado de encima y tomarlo en las manos

En este texto me propongo discutir una cita muy interesante de Benjamin, extraída de su ensayo “Historia y coleccionismo: Eduard Fuchs”

Gauge Invariance and the Pauli-Villars Regulator in Lorentz- and CPT-Violating Electrodynamics

We examine the nonperturbative structure of the radiatively induced Chern-Simons term in a Lorentz- and CPT-violating modification of QED. Although the coefficient of the induced Chern-Simons term is in general undetermined, the nonperturbative theory appears to generate a definite value. However, the CPT-even radiative corrections in this same formulation of the theory generally break gauge invariance. We show that gauge invariance may yet be preserved through the use of a Pauli-Villars regulator, and, contrary to earlier expectations, this regulator does not necessarily give rise to a vanishing Chern-Simons term. Instead, two possible values of the Chern-Simons coefficient are allowed, one zero and one nonzero. This formulation of the theory therefore allows the coefficient to vanish naturally, in agreement with experimental observations.Comment: 8 page

About Research in the Arts: a lover’s discourse

This paper is the result of an exercise of experimental re-writing and analogical thinking which had as an aim to open a new perspective on research in the arts. In terms of method, the different figures of love in Barthes' A Lover's Discourse are forced to talk about the relationship of researcher and object of study. This analogy allows us to find quality parameters based on a scale of values different to the hegemonic ones in the academy (productivity, competitiveness, innovation). These new parameters might constitute a solid ontological basis to build a new politics of artistic research in the academy that allow a radical reconsideration of processes of artistic research

Influence of the viscosity of poly(methyl methacrylate) on the cellular structure of nanocellular materials

Three different grades of poly(methyl methacrylate) (PMMA) with different rheological properties are used for the production of nanocellular materials using gas dissolution foaming. The influences of both the viscosity of the different polymers and the processing parameters on the final cellular structure are studied using a wide range of saturation and foaming conditions. Foaming conditions affect similarly all cellular materials. It is found that an increase of the foaming temperature results in less dense nanocellular materials, with higher cell nucleation densities. In addition, it is demonstrated that a lower viscosity leads to cellular polymers with a lower relative density but larger cell sizes and smaller cell nucleation densities, these differences being more noticeable for the conditions in which low solubilities are reached. It is possible to produce nanocellular materials with relative densities of 0.24 combined with cell sizes of 75 nm and cell nucleation densities of 1015 nuclei cm−3 using the PMMA with the lowest viscosity. In contrast, minimum cell sizes of around 14 nm and maximum cell nucleation densities of 3.5 × 1016 nuclei cm−3 with relative densities of 0.4 are obtained with the most viscous one. © 2019 Society of Chemical Industr