Emergence and spontaneous breaking of approximate O(4) symmetry at a weakly first-order deconfined phase transition

We investigate approximate emergent nonabelian symmetry in a class of weakly first order `deconfined' phase transitions using Monte Carlo simulations and a renormalization group analysis. We study a transition in a 3D classical loop model that is analogous to a deconfined 2+1D quantum phase transition in a magnet with reduced lattice symmetry. The transition is between the N\'eel phase and a twofold degenerate valence bond solid (lattice-symmetry-breaking) phase. The combined order parameter at the transition is effectively a four-component superspin. It has been argued that in some weakly first order `pseudocritical' deconfined phase transitions, the renormalization group flow can take the system very close to the ordered fixed point of the symmetric $O(N)$ sigma model, where $N$ is the total number of `soft' order parameter components, despite the fact that $O(N)$ is not a microscopic symmetry. This yields a first order transition with unconventional phenomenology. We argue that this occurs in the present model, with $N=4$. This means that there is a regime of lengthscales in which the transition resembles a `spin-flop' transition in the ordered $O(4)$ sigma model. We give numerical evidence for (i) the first order nature of the transition, (ii) the emergence of $O(4)$ symmetry to an accurate approximation, and (iii) the existence of a regime in which the emergent $O(4)$ is `spontaneously broken', with distinctive features in the order parameter probability distribution. These results may be relevant for other models studied in the literature, including 2+1D QED with two flavours, the `easy-plane' deconfined critical point, and the N\'eel--VBS transition on the rectangular lattice.Comment: 16 pages. v2: updated to journal versio

Topological Constraints in Directed Polymer Melts

Polymers in a melt may be subject to topological constraints, as in the example of unlinked polymer rings. How to do statistical mechanics in the presence of such constraints remains a fundamental open problem. We study the effect of topological constraints on a melt of directed polymers, using simulations of a simple quasi-2D model. We find that fixing the global topology of the melt to be trivial changes the polymer conformations drastically. Polymers of length $L$ wander in the transverse direction only by a distance of order $(\ln L)^\zeta$ with $\zeta \simeq 1.5$. This is strongly suppressed in comparison with the Brownian $L^{1/2}$ scaling which holds in the absence of the topological constraint. It is also much smaller than the predictions of standard heuristic approaches - in particular the $L^{1/4}$ of a mean-field-like `array of obstacles' model - so our results present a sharp challenge to theory. Dynamics are also strongly affected by the constraints, and a tagged monomer in an infinite system performs logarithmically slow subdiffusion in the transverse direction. To cast light on the suppression of the strands' wandering, we analyse the topological complexity of subregions of the melt: the complexity is also logarithmically small, and is related to the wandering by a power law. We comment on insights the results give for 3D melts, directed and non-directed.Comment: 4 pages + appendices, 11 figures. Published versio

Deconfinement transitions in a generalised XY model

We find the complete phase diagram of a generalised XY model that includes half-vortices. The model possesses superfluid, pair-superfluid and disordered phases, separated by Kosterlitz-Thouless (KT) transitions for both the half-vortices and ordinary vortices, as well as an Ising-type transition. There also occurs an unusual deconfining phase transition, where the disordered to superfluid transition is of Ising rather than KT type. We show by analytical arguments and extensive numerical simulations that there is a point in the phase diagram where the KT transition line meets the deconfining Ising phase transition. We find that the latter extends into the disordered phase not as a phase transition, but rather solely as a deconfinement transition. It is best understood in the dual height model, where on one side of the transition height steps are bound into pairs while on the other they are unbound. We also extend the phase diagram of the dual model, finding both O(2) loop model and antiferromagnetic Ising transitions.Comment: 19 pages. v2: references added and minor changes. Appears in "John Cardy's scale-invariant journey in low dimensions: a special issue for his 70th birthday

Audio-Visual Translation: Problems and Techniques in the Translation of Humour in Modern Family

The translation of humour is a subject in constant study –Zabalbeascoa 1996, Fuentes Luque 2001, Martínez Sierra 2006, Vandaele 2010–, due to the difficulty of translating the culture from a source text to a target text. The objective of this final degree work is to identify the problems that arise in translation for dubbing and to describe the techniques used to solve them. For this purpose, we have chosen three chapters of the sitcom Modern Family and we have analysed the original scripts and the translated ones in search of these problems and techniques. Through this analysis we have been able to see that the translation of a humorous text for dubbing presents several problems, such as the translation of puns, which is problematic due to cultural differences and time constraints. We have also explored the different ways in which a translator deals with these problems, as making adaptations or substitutions. The conclusions we have reached with this work have been that, in spite of the varied techniques for dealing with the different problems of this type of translation, the most suitable one is not always chosen. Whether it is a question of adapting the translation to the audio-visual medium, urgency within the deadlines to be met by the translator or the competence of the translator himself, the final results will vary from the original.La traducción del humor es un tema en constante estudio (Zabalbeascoa 1996, Fuentes Luque 2001, Martínez Sierra 2006, Vandaele 2010), debido a la dificultad de traducir la cultura de un texto fuente a un texto meta. El objetivo de este trabajo final de carrera es identificar los problemas que surgen en la traducción para el doblaje y describir las técnicas utilizadas para resolverlos. Para ello, hemos elegido tres capítulos de la sitcom Modern Family y hemos analizado los guiones originales y los traducidos en busca de estos problemas y técnicas. A través de este análisis hemos podido comprobar que la traducción de un texto humorístico para doblaje presenta varios problemas, como la traducción de juegos de palabras, que resulta problemática debido a las diferencias culturales y a las limitaciones de tiempo. También hemos explorado las diferentes maneras en que un traductor trata estos problemas, como hacer adaptaciones o sustituciones. Las conclusiones a las que hemos llegado con este trabajo han sido que, a pesar de la variedad de técnicas para tratar los diferentes problemas de este tipo de traducción, no siempre se elige la más adecuada. Ya se trate de la adaptación de la traducción al soporte audiovisual, de la urgencia de los plazos que debe cumplir el traductor o de la competencia del propio traductor, los resultados finales variarán con respecto al original.Grado en Estudios Inglese

Garantías económicas y sociales en Locke

With this analysis of the topic I try to identify the libertarian approaches, and consequently, I show the positions of Locke. This will allow us to tracing back the conditions of possibility for a foundation of economic and social rights from classical liberal thought. I argue that there is a contradiction between the Lockean theoretical principles and the radical approaches of libertarians, and show how from Locke appears the necessity for an economic redistribution in favor of an increasing political equality.En la posición de algunos libertarianos, los derechos sociales son inexistentes como “derechos”. Quiero ubicar primero los planteamientos principales de algunos libertarianos y posteriormente mostrar las posiciones de Locke. Esto nos permitiría rastrear las condiciones de posibilidad de fundamentación de los derechos económicos y sociales desde los orígenes del pensamiento liberal. Sostengo que existe una contradicción entre los principios teóricos planteados por Locke y  las propuestas radicales de los libertarianos y muestro el modo como desde Locke se sustenta la necesidad de la redistribución económica en aras de una mayor igualdad política

Una mirada acerca del rol docente universitario, desde las prácticas de la enseñanza en entornos no presenciales

El presente artículo presenta un resumen de la tesis doctoral desarrollada a partir de una hipótesis subyacente: el reemplazo del entorno tradicional de la enseñanza universitaria por un entorno no presencial, produciría en los docentes la necesidad de replantear sus prácticas de la enseñanza apuntando a transformar el modelo dominante; en tanto la sustitución de la clase como lugar de encuentro real entre docente y alumno por otros tipos de mediación, pone en entredicho los sustentos fundantes de dicho modelo. Se realizó tomando como estudio de caso la implementación de la Carrera de Bibliotecolo-gía a distancia, de la Universidad Nacional de Misiones (Argentina), con un enfoque predominantemente cualitativo.The present article introduces a résumé of the doctoral thesis developed from an under-lying hypothesis: the replacement of the traditional environment of the university teach-ing for a non-contact hours environment would cause professors the need to restate their teaching practices pointing to transform the prevailing model, and the substitution of the class as a real gathering place between professor and student by other kinds of means, questions the foundation of such a model. This thesis has been developed taking as a case study the implementing of the Librarian Career by distance learning of the National University of Misiones with mostly a qualitative approach

Practical guidance for easily interpreting the emission and physicochemical parameters of Eu3+ in solid-state hosts

Materials doped with the luminescent Eu3+ ion are attracting an ever-increasing amount of attention due to their potential applications in solid-state lighting, display devices, solar cells, or bioanalytics. But, why Eu3+? Unlike other lanthanides, its electronic features make the calculation of some physicochemical parameters quite straightforward, since they can be extracted directly from the emission spectrum. Highly appreciated for its reddish emission, the luminescent ion has also been widely used as a site-sensitive structural probe. With this in mind, this paper aims to offer easy guidance with helpful advice on how to interpret measurements of the emission spectra. It also presents the most useful tools for saving time, and gives a focused and practical explanation of the theoretical concepts involved.Funding for open access charge: CRUE-Universitat Jaume

The unexplored δ-phase of KY3F10: toward novel Eu3+-doped nanoplates with a ‘super-diamond’ structure for optical applications

This article describes a new, simple, and high-yield method based on a sonochemical process for obtaining the δ-KY3F10·xH2O compound with a ‘super-diamond’ structure, a material that has been completely neglected in the literature since it was first discovered. We explore the mechanism underlying the formation of the synthesized nanomaterials and show their connection with the pH of the medium. Additionally, we demonstrate for the first time the adequacy of the δ-phase of KY3F10 for optical applications through the novel Eu3+-doped nanoplates, which exhibit long lifetimes and high quantum efficiencies. The results reveal that this material, which also has zeolitic characteristics, can have a strong impact on future photonic and associated applications

Guía de social media marketing

Este proyecto desarrolla un estudio de las redes sociales aplicadas a nuevos negocios en internet, con unas necesidades definidas y con unos clientes reales. Con esta guía analizaremos las redes sociales más utilizadas por los usuarios en España y su influencia en negocios digitales. Además, trataremos de aplicar distintas estrategias de marketing digital con las que sacar provecho de las redes sociales desde el punto de vista de una empresa. Todo esto lo haremos aplicándolo a un proyecto real con una base de usuarios y clientes que nos permitirá estudiar los resultados y sacar conclusiones acerca de las estrategias planteadas