Moduli spaces of parabolic U(p,q)U(p,q)-Higgs bundles

Using the $L^2$-norm of the Higgs field as a Morse function, we count the number of connected components of the moduli space of parabolic $U(p,q)$-Higgs bundles over a Riemann surface with a finite number of marked points, under certain genericity conditions on the parabolic structure. This space is homeomorphic to the moduli space of representations of the fundamental group of the punctured surface in $U(p,q)$, with fixed compact holonomy classes around the marked points. We apply our results to the study of representations of the fundamental group of elliptic surfaces of general type.Comment: 46 pages, no figures. Corrected typos, added remarks. To appear in "Quarterly Journal of Mathematics

Abandonar suelo firme, adentrarse en los incierto : Adorno y Wagner

Este artículo ha sido realizado en el marco de los trabajos de investigación del proyecto Ministerio de Economía y Competitividad FFI2012-32614 “Experiencia estética e investigación artística: aspectos cognitivos del arte contemporáneo

The critique of causality in T. W. Adorno: A philosophicalmusical proposal through Atmosphères, by Ligeti

Este artículo está dividido en dos partes: por un lado, se delinean los puntos fundamentales de la crítica a la causalidad de T. W. Adorno y, en especial, en referencia a Aristóteles y Kant. Por otro, se explicita la deriva de esta crítica en su propio proyecto filosófico, que presta especial atención, en sus últimos años, a la música de los jóvenes compositores de Darmstadt. Atmosphères, de Ligeti se constituye como una de las obras fundamentales para dar cuenta del cruce entre filosofía y música en el pensamiento adorniano y, en concreto, con respecto al problema de la causalidadThis article has two parts: on the one hand, it attempts to outline the fundamental points of T. W. Adorno’s critique of causality and, in particular, in reference to Aristotle and Kant. On the other hand, it made explicit the drift of this criticism in his own philosophical project, which pays special attention, in his late thoughts, to the music of the young composers of Darmstadt. Ligeti’s Atmosphères is one of the fundamental works to account for the crossover between philosophy and music in Adornian thought and, in particular, with regard to the problem of causalit

El buen gobierno fiscal en la reforma mercantil del 2014 ¿Cómo introducir el tax control framework en el modelo COSO?

Treballs Finals de Grau de Dret / Administració i Direcció d'Empreses . Universitat de Barcelona. Curs: 2015-2016. Tutors: Tutors: José Andrés Rozas i María Dolores TorregrosaCon este trabajo se pretende llevar a cabo una exposición de cómo ha afectado la reforma mercantil en las sociedades de capital, en especial a las sociedades cotizadas. Además, como algo novedoso, hacer una propuesta de la manera de introducir el tax control framework dentro del sistema de control de riesgos corporativos que tienen implantadas la mayoría de sociedades

Hodge polynomials of the SL(2, C)-character variety of an elliptic curve with two marked points

We compute the Hodge polynomials for the moduli space of representations of an elliptic curve with two marked points into SL(2, C). When we fix the conjugacy classes of the representations around the marked points to be diagonal and of modulus one, the character variety is diffeomorphic to the moduli space of strongly parabolic Higgs bundles, whose Betti numbers are known. In that case we can recover some of the Hodge numbers of the character variety. We extend this result to the moduli space of doubly periodic instantons

Brauer group of moduli spaces of pairs

We show that the Brauer group of any moduli space of stable pairs with fixed determinant over a curve is zero.Comment: 12 pages. Final version, accepted in Communications in Algebr

Methodologies for teaching an engineering subject in different countries: comparison and results

Engineering or technical degrees are difficult to teach and, consequently, have always been characterized by a large number of academic failures. Therefore, continuous assessment has been applied to classes of similar content, related to Port and Coastal Engineering during these last years in three different Universities worldwide: University of La Republica (Montevideo, Uruguay), Nova de Lisboa (Portugal) and Cadiz (Spain). This paper presents different methodologies used to teach and evaluate these courses at each University, together with the results of the evaluations of the students who were enrolled during the current and previous stages. Generally, a decrease in the number of students who abandon the classes has been noticed together with an increase in the percentage of students who pass and an improvement of their grades, except at the University Nova de Lisboa were the results have remained stable. In addition, changes experienced in the courses are discussed herein by comparing the percentage of success in the different locations. Moreover, influence of the different methodologies and the possible reasons for these changes are also presented and analysed. As a conclusion, the improvement in educational outcomes has been achieved through the concurrence of different factors: the existence of more frequent written and/or oral exams, practical examples of case studies as well as access to specific tools of new technology and to documentation specifically prepared for the classes and available online. Evidently, the above mentioned tasks require a strong commitment and great effort by the teaching staff. If human resources diminish, as it is happening in Spain and Portugal due to the budget reduction in education, two difficult questions arise: For how long will teachers’ current effort be maintained? What impact will have their complete devotion to teaching in their research performance

Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)

The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence of strong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array and a self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in order to determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results show that 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoretical transport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected, which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis of different statistical grain-size parameters helped to understand sand transport distribution at different heights