AdS pure spinor superstring in constant backgrounds

In this paper we study the pure spinor formulation of the superstring in $AdS_5\times S^5$ around point particle solutions of the classical equations of motion. As a particular example we quantize the pure spinor string in the BMN background.Comment: 17 pages. Typos corrected. References adde

Feminidad hostil : la fuente pulsional de la misoginia en la cultura

Fil: Delgado, Osvaldo L. Universidad de Buenos Aires. Facultad de Psicología; Argentina.La época actual del capitalismo tardío es época de la caída de los ideales, de la\ndeclinación de la "imaco paterna", de la casi desaparición del rol del Estado y de una\ndesautorización de lo femenino en la cultura en términos freudianos. Desautorización\ndesde los varones y desde las mujeres. Estas últimas a partir del efecto combinado de\nsus luchas reivindicativas y de la incorporación masiva al mercado de trabajo. El\napronte angustiado de los varones ante lo femenino como hostil, tal como es situado\npor Freud en "El tabú de la virginidad", nombra la dimensión de lo real pulsional en\njuego en ese encuentro

Structural Changes in Data Communication in Wireless Sensor Networks

Wireless sensor networks are an important technology for making distributed autonomous measures in hostile or inaccessible environments. Among the challenges they pose, the way data travel among them is a relevant issue since their structure is quite dynamic. The operational topology of such devices can often be described by complex networks. In this work, we assess the variation of measures commonly employed in the complex networks literature applied to wireless sensor networks. Four data communication strategies were considered: geometric, random, small-world, and scale-free models, along with the shortest path length measure. The sensitivity of this measure was analyzed with respect to the following perturbations: insertion and removal of nodes in the geometric strategy; and insertion, removal and rewiring of links in the other models. The assessment was performed using the normalized Kullback-Leibler divergence and Hellinger distance quantifiers, both deriving from the Information Theory framework. The results reveal that the shortest path length is sensitive to perturbations.Comment: 12 pages, 4 figures, Central European Journal of Physic

La mirada sobre el individuo y la sociedad : la actualidad de Freud y Bataille

Fil: Delgado, Osvaldo L.. Universidad de Buenos Aires. Facultad de Psicología; Argentina.Además de su importancia explícita en el campo de la clínica psicoanalítica, la obra de Freud también\nha influido en el pensamiento sociopolítico a lo largo del siglo XX y lo sigue haciendo actualmente. A\npartir del texto "Psicología de masas y análisis del yo" -en el que Freud se pregunta ¿qué es "la\nmasa"?, ¿cuál es la relación entre masa e individuo?, ¿por qué medios el alma colectiva puede ejercer\ninfluencia en cada sujeto?, ¿en qué consiste esa influencia?-, que inspiró diversos análisis en Georges\nBataille y en otros importantes autores, se traza aquí un panorama de la actualidad de este\npensamiento, dado que las problemáticas que le dieron origen siguen plenamente vigentes

Identificaciones que colectivizan : debate sobre el ser nacional

Fil: Delgado, Osvaldo L. Universidad de Buenos Aires. Facultad de Psicología; Argentina.Promover la creencia de un ?ser nacional? puede colaborar a poner más de manifiesto las contradicciones internas en un país, ubicando a un ?agresor exterior?. Creer que hay identidad nacional abre las vías para todas las dimensiones de guerras especulares, segregación, fundamentalismo. Radicalmente, la democracia se asienta en el principio ético de que no hay ?ser?. La historia de la humanidad enseña que, cada vez que se creyó en que había un ser, ya fuera por religión, supuesta raza, tradición o ideología, la consecuencia fue trágica. ¿Qué es lo más propio que tenemos los argentinos? La lengua. El modo en que hablamos el castellano

Characterization of Vehicle Behavior with Information Theory

This work proposes the use of Information Theory for the characterization of vehicles behavior through their velocities. Three public data sets were used: i.Mobile Century data set collected on Highway I-880, near Union City, California; ii.Borl\"ange GPS data set collected in the Swedish city of Borl\"ange; and iii.Beijing taxicabs data set collected in Beijing, China, where each vehicle speed is stored as a time series. The Bandt-Pompe methodology combined with the Complexity-Entropy plane were used to identify different regimes and behaviors. The global velocity is compatible with a correlated noise with f^{-k} Power Spectrum with k >= 0. With this we identify traffic behaviors as, for instance, random velocities (k aprox. 0) when there is congestion, and more correlated velocities (k aprox. 3) in the presence of free traffic flow

New derivation for the equations of motion for particles in electromagnetism

We present equations of motion for charged particles using balanced equations, and without introducing explicitly divergent quantities. This derivation contains as particular cases some well known equations of motion, as the Lorentz-Dirac equations. An study of our main equations in terms of order of the interaction with the external field conduces us to the Landau-Lifshitz equations. We find that the analysis in second order show a special behavior. We give an explicit presentation up to third order of our main equations, and expressions for the calculation of general orders.Comment: 11 pages, 2 figures. Minor changes. Closer to published versio

Geodiversity in Pampas: Geomorphology and conservation of coastal dunes landscapes

En este trabajo se realiza una aproximación a la geodiversidad y el estado de conservación de la costa pampeana de Buenos Aires mediante el desarrollo de un estimador indirecto cualitativo, basado en variables geomorfológicas. Se analizaron imágenes de satélite y se efectuó reconocimiento en campo para la definición de paisajes según el patrón geomorfológico. Las variables de delimitación y caracterización utilizadas fueron: orientación y forma de la línea de costa; forma, textura y arreglo espacial de la vegetación; cantidad, disposición espacial y tipos de geoformas según el agente modelador y la dinámica; signos del estado dinámico del borde costero. Se calculó el porcentaje relativo de superficie correspondiente a áreas urbanas, rurales, forestales y en estado nativo, y se estimó el área protegida legalmente. Finalmente se elaboró un índice de diversidad geomorfológica, un índice de geodiversidad y otro de nivel de protección de la geodiversidad para cada paisaje. Se trabajó con la Región Costera Oriental y la Región Costera Austral (RCO y RCA) por poseer los principales campos de dunas. Éstas se subdividieron en paisajes: orientales norte y sur, y australes este, centro-este, centro, centro-oeste y oeste, respectivamente. Las regiones se diferenciaron por su orientación y extensión, pero principalmente por la calidad de los campos de dunas presentes. Se encontró que la casi totalidad de la RCO presenta modificaciones antropogénicas, y que la RCA posee la mayor parte de la geodiversidad, aunque se encuentra desprotegida legalmente en su gran mayoría. El porcentaje de área modificada por acción antrópica parece disminuir hacia el sudoeste, mostrando un patrón opuesto al de la geodiversidad, que aumenta hacia el sudoeste.Neste trabalho realiza-se um estudo à geodiversidade e ao estado de conservação da costa pampeana de Buenos Aires com o desenvolvimento de um estimador indirecto qualitativo, baseado em variáveis geomorfológicas. Analizaram-se imagens de satélite e efectuaram-se reconhecimentos de campo para a definição de paisagens segundo o padrão geomorfológico. As variáveis de delimitação e caracterização utilizadas foram: orientação e forma da linha de costa; forma, textura e arranjo espacial da vegetação; quantidade, disposição espacial e tipos de geoformas segundo o agente modelador e a dinâmica; evidências do estado dinâmico da borda costeira. Calculou-se a percentagem relativa correspondente a áreas urbanas, rurais, florestais e o estado original, e estimou-se a área protegida legalmente. Finalmente, elaborou-se um índice de diversidade geomorfológica, um índice de geodiversidade e outro do nível de protecção da geodiversidade para cada paisagem. Trabalhou-se com a Região Costeira Oriental e a Região Costeira Austral (RCO e RCA) porque possuem os principais campos dunares. Estas subdividiram-se em paisagens: orientais norte e sul, e austral este, centro-este, centro, centro-oeste e oeste, respectivamente. As regiões diferenciaram-se pela sua orientação e extensão, mas principalmente pela qualidade dos campos dunares presentes. Verificouse que a quase totalidade da RCO apresenta modificações antrópicas e que a RCA posui a maior parte da geodiversidade, embora se encontre desprotegida legalmente na sua grande maioria. A percentagem de área modificada pela acção antrópica parece diminuir para sudoeste, mostrando um padrão oposto da geodiversidade, que aumenta para sudoesteThis work presents an approach to the geodiversity and the conservation of the Pampas coast conservation in Buenos Aires, by means of the development of a qualitative indirect estimator based on geomorphological variables. Satellite images and field samples were analyzed in order to define the landscapes according to the geomorphological pattern. Demarcation and characterization variables used were: coastline shape and orientation; form, texture and spatial arrangement of vegetation; geoforms type, quantity, and spatial arrangement according to the agent modeler and the dynamics; evidence of the dynamic state of the coastline - retreating, accretion or stationary. The relative percentage of surface corresponding to urban, rural, forest and native areas was calculates and the total area legally protected was determined. Three indexes were developed for each landscape to estimate: geomorphology, geodiversity and geodiversity preservation. The work analyzes the Oriental Coastal Region and the Austral Coastal Region (RCO and RCA respectively) because they enclose the main dune fields. These regions were subdivided in landscapes: Oriental North and South, and Austral East, Center - East, Centre, Centre-West and West. Regions differed by their orientation and extension, but mainly by the quality of the present dune fields. It was found that almost the totality of the RCO presents anthropogenic modifications, and the RCA has the largest part of geodiversity, although its major surface is legally unprotected. The percentage of area modified by human action appears to decrease towards the Southwest, showing a pattern opposite to geodiversity, which increases towards the Southwest.Fil: Montserrat, A. L.. No especifíca;Fil: Codignotto, Jorge Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Secretaría de Industria y Minería. Servicio Geologico Minero Argentino; Argentin

Conformal Invariance of the Pure Spinor Superstring in a Curved Background

It is shown that the pure spinor formulation of the heterotic superstring in a generic gravitational and super Yang-Mills background has vanishing one-loop beta functions.Comment: Reference adde

Formation energy and interaction of point defects in two-dimensional colloidal crystals

The manipulation of individual colloidal particles using optical tweezers has allowed vacancies to be created in two-dimensional (2d) colloidal crystals, with unprecedented possibility of real-time monitoring the dynamics of such defects (Nature {\bf 413}, 147 (2001)). In this Letter, we employ molecular dynamics (MD) simulations to calculate the formation energy of single defects and the binding energy between pairs of defects in a 2d colloidal crystal. In the light of our results, experimental observations of vacancies could be explained and then compared to simulation results for the interstitial defects. We see a remarkable similarity between our results for a 2d colloidal crystal and the 2d Wigner crystal (Phys. Rev. Lett. {\bf 86}, 492 (2001)). The results show that the formation energy to create a single interstitial is $12$ lower than that of the vacancy. Because the pair binding energies of the defects are strongly attractive for short distances, the ground state should correspond to bound pairs with the interstitial bound pairs being the most probable.Comment: 5 pages, 2 figure