Special Geometry and Twisted Moduli in Orbifold Theories with Continuous Wilson Lines

Target space duality symmetries, which acts on K\"ahler and continuous Wilson line moduli, of a ${\bf Z}_N$ ($N\not=2$) 2-dimensional subspace of the moduli space of orbifold compactification are modified to include twisted moduli. These spaces described by the cosets $SU(n,1)\over SU(n)\times U(1)$ are $special$ K\"ahler, a fact which is exploited in deriving the extension of tree level duality transformation to include higher orders of the twisted moduli. Also, restrictions on these higher order terms are derived.Comment: 13 page

Trazos oblicuos: cuento y poes?a

121 P?ginasLibro Electr?nico1a. Ed

Charge Polarization around Impurities in Strained Graphene

Introducing quasiparticle anisotropy in graphene via uniaxial strain has a profound effect on the polarization charge density induced by external impurities, both Coulomb and short-range. In particular the charge distribution induced by a Coulomb impurity exhibits a power law tail modulated by a strain-dependent admixture of angular harmonics. The appearance of distributed charge is in sharp contrast to the response in pristine/isotropic graphene, where for subcritical impurities the polarization charge is fully localized at the impurity position. It is also interesting to note that our results are obtained strictly at zero chemical potential, and the behavior is fundamentally distinct from the typical Friedel oscillations observed at finite chemical potential. For weak to moderate strain, the $d$-wave symmetry is dominant. The presence of Dirac cone tilt, relevant to some 2D materials beyond graphene, can also substantially affect the induced charge distribution. Finally we consider impurities with short range potentials, and study the effect of strain on the charge response. Our results were obtained in the continuum via perturbation theory valid for weak (subcritical) potentials, and supported by numerical lattice simulations based on density functional theory.Comment: 11 pages, 9 figure

El juego como herramienta pedag?gica para fortalecer el nivel literal de lectura en los estudiantes de grado tercero de primaria del Colegio Montebello

151 p. Recurso Electr?nicoEste proyecto de intervenci?n pedag?gica (PIP), tiene como eje fundamental brindar a los estudiantes del grado tercero de b?sica primaria del colegio Montebello diferentes actividades orientadas a encaminar el juego como una herramienta para fortalecer el nivel descriptivo o literal de lectura, con el fin de que los ni?os y ni?as desarrollen de sus capacidades de lenguaje. Por lo tanto es necesario generar espacios de juego como medio de respeto, aprendizaje y diversi?n con la expectativa de generar un desarrollo lingu??stico orient?ndolos hacia un alto nivel cr?tico en cuanto a la lectura, sin embargo para llegar a ello se hace necesario reforzar los niveles desde su partida literal, inferencial hasta llegar a un nivel cr?tico, en los grados superiores. Desde la investigaci?n acci?n e investigaci?n formativa se pudo mejorar el proyecto ya que este nos brinda la oportunidad de tener contacto y comunicaci?n directo con los estudiantes, colegio y comunidad educativa. Por lo anterior se realizaron varias propuestas pedag?gicas entre ellas, entrevistas, talleres, videos entre otros, dise?ados para fortalecer el nivel literal de lectura. Es por ello que se tom? como herramienta el juego, por medio del cual reforzamos las tem?ticas de lectura, ya que como se conoce el juego transforma en activo lo pasivo. Este proyecto de intervenci?n se desarroll? en tres fases: la sensibilizaci?n donde se realiz? el diagn?stico inicial de los estudiantes; se evidencio la problem?tica y se encuentro una propuesta para implementar con los estudiantes del grado cuarto b?sica primaria del colegio Montebello, dando continuidad a ello realizamos la fase de intervenci?n en la cual se aplicaron los talleres que dieron respuesta a la problem?tica encontrada, la cual se bas? en fortalecer el nivel literal de lectura; para finalizar se pasa a una tercera fase: la evaluaci?n, donde se pudo evidenciar cuales fueron los alcances y la soluci?n a la problem?tica que se dio luego de haber aplicado el proyecto.This project of pedagogic intervention had as main axis to bring the students of third grade of Montebello school many activities orientated to take the game as a tool that reinforce the descriptive level of the lecture, with the purpose that the children developed their language capacities. Therefore, it?s necessary to create game spaces as a way of respect, learn and joy with the expectation to generate a linguistic development, guiding to a high level of criticism about the lecture. However, it?s required reinforce the levels since the literal definition, to an inferential and finally reach the critical standard in the major grades. With the investigation of action as well as the formative investigation were the way to improve the project that brought the opportunity to have a contact and a direct communication with the students, the school and the educative community. They were made many pedagogic approaches like interviews, videos, workshops and more, developed to strength the literal meaning of the lecture. According to this, the game was taken as a tool by which bolster the lecture thematic, the game turn around the passive to the active. This project was develop in three phases, the first one with the sensibilization and an initial diagnostic of the children, where the problematic was shown and the research and development of an approach to implement with the students of fourth grade in Montebello School. The second phase was about the intervention of the workshops that brings answers to the initial problem, making stronger the literal level of lecture. Finally the project ended with the evaluation, which displayed the scope and solutions of the problematic. Keywords. Game, reading comprehension, lecture, literal level