Quantum fluctuations on domain walls, strings, and vacuum bubbles

We develop a covariant quantum theory of fluctuations on vacuum domain walls and strings. The fluctuations are described by a scalar field defined on the classical world sheet of the defects. We consider the following cases: straight strings and planar walls in flat space, true vacuum bubbles nucleating in false vacuum, and strings and walls nucleating during inflation. The quantum state for the perturbations is constructed so that it respects the original symmetries of the classical solution. In particular, for the case of vacuum bubbles and nucleating strings and walls, the geometry of the world sheet is that of a lower-dimensional de Sitter space, and the problem reduces to the quantization of a scalar field of tachyonic mass in de Sitter space. In all cases, the root-mean-squared fluctuation is evaluated in detail, and the physical implications are briefly discussed.

Évolution des systèmes quantiques ouverts : décohérence et informatique quantique

Ce travail de maîtrise a mené à la rédaction d'un article (Physical Review A 80, 062319 (2009)).

Exportaciónes de China en Estados Unidos implicaciones comerciales para América Latina

Este trabajo estima el efecto en el nivel de las exportaciones realizadas por América Latina haciaEstados Unidos cuando se asumen los siguientes tres escenarios. Reducción del nivel de precios delos productos de origen chino, Apreciación del veinte por ciento del Renminbi.

Comments on correlation functions of large spin operators and null polygonal Wilson loops

We discuss the relation between correlation functions of twist-two large spin operators and expectation values of Wilson loops along light-like trajectories. After presenting some heuristic field theoretical arguments suggesting this relation, we compute the divergent part of the correlator in the limit of large 't Hooft coupling and large spins, using a semi-classical world-sheet which asymptotically looks like a GKP rotating string. We show this diverges as expected from the expectation value of a null Wilson loop, namely, as (ln mu(-2))(2). mu being a cut-off of the theory. (C) 2012 Elsevier B.V. All rights reserved.

Dall'involucro all'invaso. Lo spazio a pianta centrale nell'opera architettonica di Adalberto Libera

An archetype selected over the centuries Adalberto Libera wrote little, showing more inclination to use the project as the only means of verification. This study uses a survey of the project for purely compositional space in relation to the reason that most other returns with continuity and consistency throughout his work. "The fruit of a type selected over centuries", in the words of Libera, is one of the most widely used and repeated spatial archetypes present in the history of architecture, given its nature as defined by a few consolidated elements and precisely defined with characters of geometric precision and absoluteness, the central space is provided, over the course of evolution of architecture, and its construction aspects as well as symbolic, for various uses, from historical period in which it was to coincide with sacred space for excellence, to others in which it lends itself to many different expressive possibilities of a more "secular". The central space was created on assumptions of a constructive character, and the same exact reason has determined the structural changes over the centuries, calling from time to time with advances in technology, the maximum extent possible and the different applications, which almost always have coincided with the reason for the monumental space. But it’s in the Roman world that the reason for the central space is defined from the start of a series of achievements that fix the character in perpetuity. The Pantheon was seen maximum results and, simultaneously, the archetype indispensable, to the point that it becomes difficult to sustain a discussion of the central space that excludes. But the reason the space station has complied, in ancient Rome, just as exemplary, monuments, public spaces or buildings with very different implications. The same Renaissance, on which Wittkower's proving itself once and for all, the nature and interpretation of sacred space station, and thus the symbolic significance of that invaded underlying interpretations related to Humanism, fixing the space-themed drawing it with the study and direct observation by the four-sixteenth-century masters, the ruins that in those years of renewed interest in the classical world, the first big pieces of excavation of ancient Rome brought to light with great surprise of all. Not a case, the choice to investigate the architectural work of Libera through the grounds of the central space. Investigating its projects and achievements, it turns out as the reason invoked particularly evident from the earliest to latest work, crossing-free period of the war which for many authors in different ways, the distinction between one stage and another, or the final miss. The theme and the occasion for Libera always distinct, it is precisely the key through which to investigate her work, to come to discover that the first-in this case the central plan-is the constant underlying all his work, and the second reason that the quota with or at the same time, we will return different each time and always the same Libera, formed on the major works remained from ancient times, and on this building method, means consciously, that the characters of architectural works, if valid, pass the time, and survive the use and function contingent. As for the facts by which to formalize it, they themselves are purely contingent, and therefore available to be transferred from one work to another, from one project to another, using also the loan. Using the same two words-at-issue and it becomes clear now how the theme of this study is the method of Libera and opportunity to the study of the central space in his work. But there is one aspect that, with respect to space a central plan evolves with the progress of the work of Libera on the archetype, and it is the reason behind all the way, just because an area built entirely on reason centric. It 'just the "center" of space that, ultimately, tells us the real progression and the knowledge that over the years has matured and changed in Libera. In the first phase, heavily laden with symbolic superstructure, even if used in a "bribe" from Free-always ill-disposed to sacrifice the idea of architecture to a phantom-center space is just the figure that identifies the icon represents space itself: the cross, the flame or the statue are different representations of the same idea of center built around an icon. The second part of the work of clearing the space station, changed the size of the orders but the demands of patronage, grows and expands the image space centric, celebratory nature that takes and becomes, in a different way, this same symbol . You see, one in all, as the project of "Civiltà Italiana" or symbolic arch are examples of this different attitude. And at the same point of view, you will understand how the two projects formulated on the reuse of the Mausoleum of Augustus is the key to its passage from first to second phase: the Ara Pacis in the second project, making itself the center of the composition "breaks" the pattern of symbolic figure in the center, because it is itself an architecture. And, in doing so, the transition takes place where the building itself-the central space-to become the center of that space that itself creates and determines, by extending the potential and the expressiveness of the enclosure (or cover) that defines the basin centered. In this second series of projects, which will be the apex and the point of "crisis" in the Palazzo dei Congressi all'E42 received and is no longer so, the symbol at the very geometry of space, but space itself and 'action' will be determined within this; action leading a movement, in the case of the Arco simbolico and the "Civiltà Italiana" or, more frequently, or celebration, as in the great Sala dei Recevimenti all’E42, which, in the first project proposal, is represented as a large area populated by people in suits, at a reception, in fact. In other words, in this second phase, the architecture is no longer a mere container, but it represents the shape of space, representing that which "contains". In the next step-determining the knowledge from which mature in their transition to post-war-is one step that radically changes the way centric space, although formally and compositionally Libera continues the work on the same elements, compounds and relationships in a different way . In this last phase Freedom, center, puts the man in human beings, in the two previous phases, and in a latent, were already at the center of the composition, even if relegated to the role of spectators in the first period, or of supporting actors in the second, now the heart of space. And it’s, as we shall see, the very form of being together in the form of "assembly", in its different shades (up to that sacred) to determine the shape of space, and how to relate the parts that combine to form it. The reconstruction of the birth, evolution and development of the central space of the ground in Libera, was born on the study of the monuments of ancient Rome, intersected on fifty years of recent history, honed on the constancy of a method and practice of a lifetime, becomes itself, Therefore, a project, employing the same mechanisms adopted by Libera; the decomposition and recomposition, research synthesis and unity of form, are in fact the structure of this research work. The road taken by Libera is a lesson in clarity and rationality, above all, and this work would uncover at least a fragment.

Oriente y mundo clásico en José Vasconcelos

En muchos aspectos el pensamiento de José Vasconcelos (1882–1959) sufrió cambios notables durante su vida. Sus ideas sobre el mundo clásico grecorromano y el Oriente también los experimentaron. A diferencia de sus contemporáneos reunidos en el Ateneo de la Juventud, fue crítico del mundo clásico y buscó fuentes de inspiración estética y moral en la India, mostró curiosidad por el Japón y por el Islam. Sus ideas sobre el mestizaje y la "raza cósmica" deben mucho a este interés. Con los años, sin embargo, su creciente conservatismo también influyó en sus ideas sobre el mundo clásico y el Oriente. Este último le fue cada vez más alejado, sobre todo el Islam, objeto de su odio principal. Como ello se daba cuando otros intelectuales enrolados en la izquierda ensayaban un movimiento de simpatía hacia el mundo colonial, contribuyeron a exacerbar la reacción de Vasconcelos.

Etapas de la recepción clásica en la obra de Luis Franco

En este trabajo describimos sintéticamente las etapas en que puede ser dividida la obra de Luis Franco a partir de la presencia y la función de las culturas griega y romana en algunos de sus principales libros. A través de ejemplos, señalamos las características más notables de recepción de la cultura clásica, algunos procesos de selección y modos de apropiación del mundo clásico que Luis Franco practicó desde una perspectiva deliberadamente no académica sino autodidacta y personal

La antigüedad como modelo : Tradición clásica en generaciones y semblanzas del humanista Fernán Pérez de Guzmán

La historiografía grecolatina había hecho de la biografía un género cuya materia: la vida y los hechos de un personaje ejemplar, se presentaba inseparable de la forma y las prescripciones de la retórica. En los siglos del Renacimiento, avalada por el prestigio de la antigüedad clásica y de su tradición, la biografía experimenta un gran impulso por su doble carácter moralizante y propagandístico en un contexto histórico en el que aristócratas y monarcas luchan con las armas y con las letras por la preeminencia. En este trabajo estudiaremos tanto las influencias de la biografía antigua, como el uso y la función de los motivos procedentes del mundo clásico en Generaciones y semblanzas de Fernán Pérez de Guzmán, uno de los escritores más importantes del primer humanismo español, autor al que se ha considerado un modelo de espontaneidad y originalidad.

La antigüedad como modelo : Tradición clásica en generaciones y semblanzas del humanista Fernán Pérez de Guzmán

La historiografía grecolatina había hecho de la biografía un género cuya materia: la vida y los hechos de un personaje ejemplar, se presentaba inseparable de la forma y las prescripciones de la retórica. En los siglos del Renacimiento, avalada por el prestigio de la antigüedad clásica y de su tradición, la biografía experimenta un gran impulso por su doble carácter moralizante y propagandístico en un contexto histórico en el que aristócratas y monarcas luchan con las armas y con las letras por la preeminencia. En este trabajo estudiaremos tanto las influencias de la biografía antigua, como el uso y la función de los motivos procedentes del mundo clásico en Generaciones y semblanzas de Fernán Pérez de Guzmán, uno de los escritores más importantes del primer humanismo español, autor al que se ha considerado un modelo de espontaneidad y originalidad.

Etapas de la recepción clásica en la obra de Luis Franco

En este trabajo describimos sintéticamente las etapas en que puede ser dividida la obra de Luis Franco a partir de la presencia y la función de las culturas griega y romana en algunos de sus principales libros. A través de ejemplos, señalamos las características más notables de recepción de la cultura clásica, algunos procesos de selección y modos de apropiación del mundo clásico que Luis Franco practicó desde una perspectiva deliberadamente no académica sino autodidacta y personal

La antigüedad como modelo : Tradición clásica en generaciones y semblanzas del humanista Fernán Pérez de Guzmán

La historiografía grecolatina había hecho de la biografía un género cuya materia: la vida y los hechos de un personaje ejemplar, se presentaba inseparable de la forma y las prescripciones de la retórica. En los siglos del Renacimiento, avalada por el prestigio de la antigüedad clásica y de su tradición, la biografía experimenta un gran impulso por su doble carácter moralizante y propagandístico en un contexto histórico en el que aristócratas y monarcas luchan con las armas y con las letras por la preeminencia. En este trabajo estudiaremos tanto las influencias de la biografía antigua, como el uso y la función de los motivos procedentes del mundo clásico en Generaciones y semblanzas de Fernán Pérez de Guzmán, uno de los escritores más importantes del primer humanismo español, autor al que se ha considerado un modelo de espontaneidad y originalidad.

Etapas de la recepción clásica en la obra de Luis Franco

En este trabajo describimos sintéticamente las etapas en que puede ser dividida la obra de Luis Franco a partir de la presencia y la función de las culturas griega y romana en algunos de sus principales libros. A través de ejemplos, señalamos las características más notables de recepción de la cultura clásica, algunos procesos de selección y modos de apropiación del mundo clásico que Luis Franco practicó desde una perspectiva deliberadamente no académica sino autodidacta y personal

The Formation and Circulation of Early Yanzi Lore, Fourth Century B.C. - Third Century A.D.

Thesis (Ph.D.)--University of Washington, 2016-06