From Scale-free to Erdos-Renyi Networks

We analyze a model that interpolates between scale-free and Erdos-Renyi networks. The model introduced generates a one-parameter family of networks and allows to analyze the role of structural heterogeneity. Analytical calculations are compared with extensive numerical simulations in order to describe the transition between these two important classes of networks. Finally, an application of the proposed model to the study of the percolation transition is presented.Comment: 8 pages, 6 figure

Explosive Synchronization Transitions in Scale-free Networks

The emergence of explosive collective phenomena has recently attracted much attention due to the discovery of an explosive percolation transition in complex networks. In this Letter, we demonstrate how an explosive transition shows up in the synchronization of complex heterogeneous networks by incorporating a microscopic correlation between the structural and the dynamical properties of the system. The characteristics of this explosive transition are analytically studied in a star graph reproducing the results obtained in synthetic scale-free networks. Our findings represent the first abrupt synchronization transition in complex networks thus providing a deeper understanding of the microscopic roots of explosive critical phenomena.Comment: 6 pages and 5 figures. To appear in Physical Review Letter

A note on the dyonic D6-brane

We study the dyon electric charge of D6-branes as eleven dimensional KK-monopoles. We observe that the dyon charge is intimately related with the existence of gauge connections and antisymmetric fields on the brane world volume.Comment: 8 pages, Contribution to the 6th International Workshop on Conformal Field Theory and Integrable Models, Landau Institute, Sept. 2002, to honour A. Belavin on the occasion of his 60th birthda

On the nature of an ejection event in the jet of 3C111

We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec. The first component evolves downstream, whereas the second one fades out after 1 parsec. We propose the injection of a perturbation of dense material followed by a decrease in the injection rate of material in the jet as a plausible explanation. This scenario is supported by 1D relativistic hydrodynamics and emission simulations. The perturbation is modeled as an increase in the jet density, without modifying the original Lorentz factor in the initial conditions. We show that an increase of the Lorentz factor in the material of the perturbation fails to reproduce the observed evolution of this flare. We are able to estimate the lifetime of the ejection event in 3C111 to be 36\pm7 days.Comment: Accepted for publication in Astronomy & Astrophysics Letter

Presente y futuro de la investigación, la innovación y el desarrollo de la intervención social con familias (Complemento práctico al capítulo 16 del libro: Intervención social con familias)

El presente documento complementario del tema 16 del libro incluye los archivos informáticos (documentos de texto, hojas de cálculo, páginas web) que, como integrantes del documento, han sido citados en el texto. También incluye otros archivos que se citan en este documento o que son necesarios para su funcionamiento. Los puede encontrar y consultar en el Centro del Estudiante, en el apartado Documentos de Trabajo. Este documento es interactivo. Están marcados los enlaces a las distintas partes del mismo para facilitar el acceso rápido a las mismas. Complementos I: Tratamiento personalizado de los datos de las encuestas. Complemento 16.1. Valoración de respuestas con lógica difusa. Complemento 16.2. Ordenación de datos de encuestas. Complemento 16.3. Aplicaciones sencillas de tratamiento de datos. Complementos II: Aplicación a la intervención social de los resultados del tratamiento de datos. Complemento 16.4. Práctica de ordenación de datos de encuestas de intervención social. Complemento 16.5. Práctica de tratamiento de datos de encuestas de intervención social. Complemento 16.6. Ejemplo de aplicación en la línea de investigación de constelaciones organizacionales