Circular Wilson loops in defect conformal field theory

We study a D3-D5 system dual to a conformal field theory with a codimension-one defect that separates regions where the ranks of the gauge groups differ by k. With the help of this additional parameter, as observed by Nagasaki, Tanida and Yamaguchi, one can define a double scaling limit in which the quantum corrections are organized in powers of λ/k2, which should allow to extrapolate results between weak and strong coupling regimes. In particular we consider a radius R circular Wilson loop placed at a distance L, whose internal space orientation is given by an angle χ. We compute its vacuum expectation value and show that, in the double scaling limit and for small χ and small L/R, weak coupling results can be extrapolated to the strong coupling limit.Fil: Aguilera Damia, Jeremías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Correa, Diego Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Giraldo Rivera, Victor Ivan. International Centre For Theoretical Sciences; India. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Commutative Finitely Generated Algebras Satisfying ((yx)x)x = 0 are Solvable

We study commutative, nonassociative algebras satisfying the identity (1) ((yx)x)x = 0 We show that finitely generated algebras over a field K of characteristic ≠ 2 satisfying (1) are solvable. For x in an algebra A, define the multiplicatin operator Rx by yRx = yx, for all y ∈ A. Our identify is then that Rx3 = 0

Introducción al problema de la erosión litoral en Urabá (sector Arboletes - Turbo), Costa Caribe Colombiana

Introduction to littoral erosion problem in Urabá (Arboletes-Turbo area) Colombian Caribbean coast. Shoreline retreat has been the net dominant historical trend along the 145 km-length littoral between Arboletes and Turbo (Southern Caribbean of Colombia). For the last four decades, there were identified in this littoral shoreline retreats of about 50-100m in several places (Uveros, Damaquiel, Zapata, Turbo) and a maximun of 1.6 km in the Punta Rey-Arboletes area, where land losses were of 4.5 k m2, at exceptional rates of 40m/year. The synthesis of the available information suggest that the general “susceptibility” to erosion between Arboletes and Turbo could be related primarily to relative sea level rise, associated to tectonic movements as well as to the effects of mud diapirism and hydroisostacy. In the more critical areas (Arboletes, Turbo), the natural erosive trends were accelerated by anthropic actions, including river diversion (Turbo), beach mining, and inadequate (or total absense) practices for controlling residual and natural waters. Up to August 2000, there were invested about $Col 10.000 billions in 155 engineering defences (groins, sea walls and rip-rap which totalize 6.2 km of total length and a volume of materials of 37.000 m3). With few exceptions, groins have not been successful and are now part of the problem, accelerating shore erosion along the adyacent sectors. In the short term, the littoral erosion between Arboletes and Turbo is caused both by marine and by subaerial factors. It is facilitated by the poor lithological strengths of cliffs and marine terraces, mainly composed of highly fractured and weathered claystones and mudstones (with stratification and weakeness planes dipping toward sea) and nonconsolidated, easily liquefacted, fine sediments; both conditions facilitate the occurrence of rocks falls, slides and mud flows that result in high figures of cliff retreat (3 to 4m), specially during the first 15 days of the summer-winter transition (april) and in high waves periods. The case of the littoral erosion between Arboletes and Turbo illustrates well how the natural erosive trends of an area can be accelerated by human interventions and the urgent need for coordinating efforts to cope with littoral land losses.La erosión litoral ha sido la tendencia histórica dominante a lo largo de los aproximadamente 145 km de línea de costa entre las ciudades de Arboletes y Turbo (sur del Litoral Caribe colombiano). En las cuatro últimas décadas ocurrieron retrocesos de la línea de costa del orden de los 50-100m en varios sectores (Uveros, Damaquiel, Zapata, Turbo), y de hasta 1.6 km en el área Punta Rey-Arboletes, en la cual las pérdidas de terrenos suman más de 4.5 km2 y la erosión alcanzó tasas máximas de hasta 40m/año. La síntesis de la información disponible sugiere que la “susceptibilidad” generalizada a la erosión podría ser la respuesta a ascensos relativos del nivel del mar, asociados a la tectónica regional, a los efectos del diapirismo de lodos y a la hidroisostacia, entre otros posibles factores. En los sectores más críticos (Arboletes y Turbo), las tendencias erosivas naturales fueron aceleradas por intervenciones humanas como la desviación del río Turbo, la extracción intensiva de materiales de playa y el manejo inadecuado (o no manejo) de las aguas lluvias y residuales. El costo actualizado de las 155 obras de defensa (espolones, barreras y muros de contención que totalizan 6.2 km de longitud y un volumen de materiales de 37.000m3) construidas hasta agosto del 2000 se calcula en alrededor de los$ Col 10.000 millones. Con muy pocas excepciones, los espolones perpendiculares a las playas no han recuperado arenas y más bien se han convertido en generadores de nuevos problemas en los sectores adyacentes. A corto plazo, la erosión litoral entre Arboletes y Turbo es causada tanto por factores marinos como por procesos de erosión subaérea y es función en buena parte de las litologías poco resistentes de las terrazas y acantilados, compuestos en su mayoría por lodolitas fracturadas y meteorizadas (con buzamientos o planos de debilidad inclinados hacia el mar) y por sedimentos finos no consolidados, fácilmente licuables: ambas condiciones facilitan la ocurrencia de deslizamientos, caídas de rocas y flujos de lodo que determinan retrocesos rápidos (3 a 4 metros) del contorno litoral, sobre todo en los primeros 15 días de la transición verano-invierno (abril) y durante los “mares de leva” (periodos de oleajes fuertes). El caso de la erosión litoral entre Turbo y Arboletes ilustra claramente cómo las tendencias erosivas naturales pueden intensificarse fuertemente por intervenciones humanas (incluyendo las defensas ingenieriles) y la necesidad urgente de coordinar esfuerzos para controlar o mitigar con eficiencia las pérdidas de terrenos litorales

Solvability of Commutative Right-Nilalgebras Satisfying (b (aa)) a= b ((aa) a)

We study commutative right-nilalgebras of right-nilindex four satisfying the identity (b(aa))a = b((aa)a). Our main result is that these algebras are solvable and not necessarily nilpotent. Our results require characteristic ≠ 2, 3, 5

Combined beach - inner shelf erosion in short and medium term (Maspalomas, Canary Islands)

The analysis of the accurate topo-bathymetric digital elevation model (DEM), the cartography of the submarine sedimentary cover and the monitoring of short (seasonal) and medium-term (2000-2009) morphological changes have permitted depicting the erosional trend in the short and medium-term of the Maspalomas sedimentary system. Short-term analysis showed intense sedimentary fluxes between the beaches and the inner shelf, and sedimentary exchanges with other sectors of the inner shelf, while the steep slope inner shelf fronting La Bajeta cape was identified as a sink area. In the medium-term the sediment budget showed high erosion of the supratidal and intertidal sectors of the beaches due to storm waves in the 2005-2006 winter, followed by accretion over the next four years, but which did not reach the initial sedimentary state. The inner shelf and subtidal sector of the beaches showed negative budgets in the short and medium-term. Interannual variability of the wave and wind regimes determines decadal beach erosion-accretion cycles, while long-term climatic change, evidenced at the study area by a decrease of trade winds and NE wave intensity in 2005, is expected to produce a possible increase of erosion at the El Inglés inner shelf and consequently a decrease in sediment inputs to the El Inglés beach and Maspalomas dune field. Finally, the influence of the geological heritage is depicted by the Fataga gully’s control of the present coastal morphology, and by the island relief control of the wind, waves and current directions in the study area

Supersymmetric mixed boundary conditions in AdS2 and DCFT1 marginal deformations

We consider different supersymmetric mixed boundary conditions for scalar and fermionic fields in AdS2, searching for the dual description of a family of interpolating Wilson Loops in ABJM theory. The family, which interpolates between the bosonic 1/6 BPS loop and the 1/2 BPS loop, can be thought of as an exact marginal deformation in a defect CFT1. Confronting this property against holographic correlators and vacuum energy corrections singles out a particular boundary condition which we propose as dual to the interpolating family of Wilson loops.Fil: Correa, Diego Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Giraldo Rivera, Victor Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Silva, Guillermo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; Argentin