Higgs bundles and surface group representations in the real symplectic group

In this paper we study the moduli space of representations of a surface group (i.e., the fundamental group of a closed oriented surface) in the real symplectic group Sp(2n,R). The moduli space is partitioned by an integer invariant, called the Toledo invariant. This invariant is bounded by a Milnor-Wood type inequality. Our main result is a count of the number of connected components of the moduli space of maximal representations, i.e. representations with maximal Toledo invariant. Our approach uses the non-abelian Hodge theory correspondence proved in a companion paper arXiv:0909.4487 [math.DG] to identify the space of representations with the moduli space of polystable Sp(2n,R)-Higgs bundles. A key step is provided by the discovery of new discrete invariants of maximal representations. These new invariants arise from an identification, in the maximal case, of the moduli space of Sp(2n,R)-Higgs bundles with a moduli space of twisted Higgs bundles for the group GL(n,R).Comment: 55 pages; v2: main results are unchanged but paper has been completely reorganized and presentation significantly improved; v3, v4: various corrections and improvements; Part 1 of v2 has been split off as the independent paper arXiv:0909.4487v1 [math.DG

Croniquilla de New York : felicitación

Abstract not availabl

Hole-Pairs in a Spin Liquid: Influence of Electrostatic Hole-Hole Repulsion

The stability of hole bound states in the t-J model including short-range Coulomb interactions is analyzed using computational techniques on ladders with up to $2 \times 30$ sites. For a nearest-neighbors (NN) hole-hole repulsion, the two-holes bound state is surprisingly robust and breaks only when the repulsion is several times the exchange $J$. At $\sim 10$ hole doping the pairs break only for a NN-repulsion as large as $V \sim 4J$. Pair-pair correlations remain robust in the regime of hole binding. The results support electronic hole-pairing mechanisms on ladders based on holes moving in spin-liquid backgrounds. Implications in two dimensions are also presented. The need for better estimations of the range and strength of the Coulomb interaction in copper-oxides is remarked.Comment: Revised version with new figures. 4 pages, 5 figure

Análisis Contable y Financiero: Una Herramienta Clave Para La Eficiente Gestión Financiera Y Contable En La Empresa/Accounting and Financial Analysis: A Key Tool for Efficient Financial and Accounting Management in the Company

El análisis financiero y contable es fundamental para evaluar el rendimiento real económico, financiero y contable de una empresa, detectar dificultades y aplicar las medidas correctivas necesarias para resolverlos. La información contable que se refleja en los estados financieros como el balance general, cuenta de resultados, y el estado de flujos de efectivo en forma de datos resumidos. Sin embargo, para que los datos sean útiles para los usuarios de los estados financieros y contables, deben estar claramente analizados. Algunas de las maneras de analizar incluyen el uso de ratios, análisis de flujo de efectivo y análisis vertical y horizontal. De este contexto, en este estudio se evaluó la importancia del análisis financiero y contable como una herramienta clave para administrar la empresa eficientemente. El estudio fue analítico en el ámbito de aplicación con diseño documental basado en los fundamentos teóricos de diversos autores. Los resultados más relevantes del análisis indicaron que las empresas, privadas, instituciones públicas y de gobierno hacen hincapié en el uso de análisis de estados financieros como una herramienta para determinar la liquidez, solvencia, precio de las acciones, rentabilidad, crecimiento del negocio y pronósticos. The financial and accounting analysis is fundamental to evaluate the real economic, financial and accounting performance of a company, detect difficulties and apply the necessary corrective measures to solve them. The accounting information in the form of financial statements such as the balance sheet, income statement, and the statement of cash flows in the form of summary data. However, for the data to be useful for the users of the financial and accounting statements they must be analyzed. Some of the ways to analyze include the use of ratios, cash flow analysis and vertical and horizontal analysis. In this context, this study will evaluate the importance of financial and accounting analysis as a key tool to manage the company efficiently. The study will be analytical in the scope of application with documentary design based on the theoretical foundations of various authors. The most relevant results of the analysis indicate that companies, private, public and government institutions emphasize the use of financial statement analysis as a tool to determine liquidity, solvency, share price, profitability, business growth and forecasts. Palabras clave: contable, financiero, eficiencia, gestión, empresa. Keywords: accounting, financial, efficiency, management, company

Gender Incidence in the Salary of Informal Workers for the Management of Socioeconomic Strategies

This research examined the problems experienced by women who work in the informal sector of the city of Riobamba due to receiving poor and lower incomes than men. The main objective was to analyze the influence that gender has on wages of women in this sector, to establish strategies that can promote more equitable development. Qualitative and quantitative approaches were used using inductive and deductive methods. Data were collected through a survey and analyzed using the Chi square test. The results showed that women's wages were dependent on their gender, conditioned by a sociocultural environment that has not evolved, especially in the informal sectors made up mostly of rural population. Also, the presence of child labor was evident, and wages could not cover the basic needs of women who identified as heads of household with family responsibilities of between three to five people. The strategy identified to promote equity in the recognition and value of fair work without distinction of gender was based on the following elements: the implementation of inclusion policies and control, training of young women in non-traditional trades, promotion of changes in traditional patterns in households, and policies to combat poverty with a gender focus for sustainable social development. Keywords: gender, equity, salary, strategies, socioeconomic, management. Resumen La investigación plantea la problemática que viven las mujeres que trabajan en el sector informal de la ciudad de Riobamba debido a su condición de género para percibir ingresos deficientes e inferiores a los hombres, el objetivo principal es analizar la incidencia que tiene el género en el salario de las mujeres de este sector para el establecimiento de estrategias que promuevan un desarrollo más equitativo. La metodología investigativa considera estudios analíticos, correlacionales, exploratorios, de campo, un enfoque cuali- cuantitativo, con métodos inductivos y deductivos, usando técnicas como la encuesta, considerado la relación de dependencia a través del Chi cuadrado para la comprobación de la hipótesis, como resultados principales se puede encontrar que la incidencia del género en los salarios de las mujeres es dependiente, condicionado por un ambiente sociocultural que no ha evolucionado sobre todo en los sectores informales conformados en su mayoría por población rural, se evidencia la presencia del trabajo infantil y salarios que no pueden cubrir las necesidades básicas de mujeres que se identifican como jefes de hogar con cargas familiares de entre 3 a 5 personas, se plantea como solución la estrategia para promover la equidad en el reconocimiento y puesta en valor del trabajo equitativo sin distinción de género basada en 5 elementos: la implementación de políticas de inclusión y control, la capacitación de las jóvenes en oficios no tradicionales, promoción de cambios de patrones tradicionales en los hogares, políticas de combate a la pobreza con enfoque de género para un desarrollo social sustentable. Palabras clave: género, equidad, salario, estrategias, socioeconómicas, gestión

Trapped surfaces and emergent curved space in the Bose-Hubbard model

A Bose-Hubbard model on a dynamical lattice was introduced in previous work as a spin system analogue of emergent geometry and gravity. Graphs with regions of high connectivity in the lattice were identified as candidate analogues of spacetime geometries that contain trapped surfaces. We carry out a detailed study of these systems and show explicitly that the highly connected subgraphs trap matter. We do this by solving the model in the limit of no back-reaction of the matter on the lattice, and for states with certain symmetries that are natural for our problem. We find that in this case the problem reduces to a one-dimensional Hubbard model on a lattice with variable vertex degree and multiple edges between the same two vertices. In addition, we obtain a (discrete) differential equation for the evolution of the probability density of particles which is closed in the classical regime. This is a wave equation in which the vertex degree is related to the local speed of propagation of probability. This allows an interpretation of the probability density of particles similar to that in analogue gravity systems: matter inside this analogue system sees a curved spacetime. We verify our analytic results by numerical simulations. Finally, we analyze the dependence of localization on a gradual, rather than abrupt, fall-off of the vertex degree on the boundary of the highly connected region and find that matter is localized in and around that region.Comment: 16 pages two columns, 12 figures; references added, typos correcte

The complex structure of HH 110 as revealed from Integral Field Spectroscopy

HH 110 is a rather peculiar Herbig-Haro object in Orion that originates due to the deflection of another jet (HH 270) by a dense molecular clump, instead of being directly ejected from a young stellar object. Here we present new results on the kinematics and physical conditions of HH 110 based on Integral Field Spectroscopy. The 3D spectral data cover the whole outflow extent (~4.5 arcmin, ~0.6 pc at a distance of 460 pc) in the spectral range 6500-7000 \AA. We built emission-line intensity maps of H$\alpha$, [NII] and [SII] and of their radial velocity channels. Furthermore, we analysed the spatial distribution of the excitation and electron density from [NII]/H$\alpha$, [SII]/H$\alpha$, and [SII] 6716/6731 integrated line-ratio maps, as well as their behaviour as a function of velocity, from line-ratio channel maps. Our results fully reproduce the morphology and kinematics obtained from previous imaging and long-slit data. In addition, the IFS data revealed, for the first time, the complex spatial distribution of the physical conditions (excitation and density) in the whole jet, and their behaviour as a function of the kinematics. The results here derived give further support to the more recent model simulations that involve deflection of a pulsed jet propagating in an inhomogeneous ambient medium. The IFS data give richer information than that provided by current model simulations or laboratory jet experiments. Hence, they could provide valuable clues to constrain the space parameters in future theoretical works.Comment: 12 pages, 15 figures Accepted in MNRA

La problemática de las murallas en el crecimiento de la Ciutat de Mallorca

Abstract not availabl