Higher spin matrix models

We propose a hybrid class of theories for higher spin gravity and matrix models, i.e. which handle simultaneously higher spin gravity fields and matrix models. The construction is similar to Vasiliev's higher spin gravity but part of the equations of motion are provided by the action principle of a matrix model. In particular we construct a higher spin (gravity) matrix model related to type IIB matrix models/string theory which have a well defined classical limit, and which is compatible with higher spin gravity in $AdS$ space. As it has been suggested that higher spin gravity should be related to string theory in a high energy (tensionless) regime, and therefore to M-Theory, we expect that our construction will be useful to explore concrete connections.Comment: 13 pages, 1 table. New references and corrections from referee reports are included in this version. Current form accepted in Universe journal for the special issue on Higher Spin Gauge Theorie

Backreaction in Axion Monodromy, 4-forms and the Swampland

Axion monodromy models can always be described in terms of an axion coupled to 3-form gauge fields with non-canonical kinetic terms. The presence of the saxions parametrising the kinetic metrics of the 3-form fields leads to backreaction effects in the inflationary dynamics. We review the case in which saxions backreact on the K\"ahler metric of the inflaton leading to a logarithmic scaling of the proper field distance at large field. This behaviour is universal in Type II string flux compactifications and consistent with a refinement of the Swampland Conjecture. The critical point at which this behaviour appears depends on the mass hierarchy between the inflaton and the saxions. However, in tractable compactifications, such a hierarchy cannot be realised without leaving the regime of validity of the effective theory, disfavouring transplanckian excursions in string theory.Comment: Proceedings prepared for the "Workshop on Geometry and Physics", November 2016, Ringberg Castl

Higher Spin Symmetries and Deformed Schr\"odinger Algebra in Conformal Mechanics

The dynamical symmetries of $1+1$-dimensional Matrix Partial Differential Equations with a Calogero potential (with/without the presence of an extra oscillatorial De Alfaro-Fubini-Furlan, DFF, damping term) are investigated. The first-order invariant differential operators induce several invariant algebras and superalgebras. Besides the $sl(2)\oplus u(1)$ invariance of the Calogero Conformal Mechanics, an $osp(2|2)$ invariant superalgebra, realized by first-order and second-order differential operators, is obtained. The invariant algebras with an infinite tower of generators are given by the universal enveloping algebra of the deformed Heisenberg algebra, which is shown to be equivalent to a deformed version of the Schr\"odinger algebra. This vector space also gives rise to a higher spin (gravity) superalgebra. We furthermore prove that the pure and DFF Matrix Calogero PDEs possess isomorphic dynamical symmetries, being related by a similarity transformation and a redefinition of the time variable.Comment: Final version to appear in Adv. Math. Phy

Bimetallic au/ag metal superstructures from macromolecular metal complexes in solid-state

Indexación: Web of Science; Scielo.Novel bimetallic Au/Ag superstructures have been prepared from solid-state pyrolysis of the macromolecular complexes Chitosan(MLn/M'Ln)n y PSP-4-PVPx( MLn/M'Ln)n with MLn = AuCl3 and M'Ln = Ag(CF3SO3)The characterization was made from XRD (X-ray diffraction of powder), SEM and EDS analysis. Morphologies are influenced by both the nature of the polymer and the metal/polymer, molar ratio of the polymer precursor. EDS analysis suggests a core/shell Au/Ag structure for the materials. A probable mechanism of the formation of these superstructures is discussed. Although separated reports of metallic superstructures of Au or Ag have been recently described, the here reported are the first bimetallic Au/Ag. Key words: Superstructures, Macromolecular complexes, metallic Au and Ag, Pyrolysishttp://ref.scielo.org/y6jcg

Sorption of apolar pesticides by units of benzoic acid propyl ester in cyclic phosphazene

Indexación: Scopus.The effects of temperature, pH and agitation time (equilibrium) on the adsorption process of different pesticides on N3P3(OC6H4COOCH2CH2CH3)6 was studied. With optimal conditions experimental, the adsorption isotherms have been realized with through Langmuir and Freundlich models. Pesticides are compounds used mainly in agriculture to control various species (plants, insects, worms, fungi). Due to their physicochemical properties, they can remain for a long time in the application sites, bioaccumulating and moving between environmental compartments which generate various environmental problems. The results obtained showed a physisorption mechanism for the fve pesticides studied, with higher sorption for: azinphos methyl (93,5 mg kg-1), carbaryl (290.5 mg kg-1) and carbofuran (580.5 mg kg-1) at 20 ° C, according to the models used. © 2018 Sociedad Chilena de Quimica. All rights reserved.https://scielo.conicyt.cl/pdf/jcchems/v62n4/0717-9324-jcchems-62-04-3783.pd

Topological self-dual vacua of deformed gauge theories

We propose a deformation principle of gauge theories in three dimensions that can describe topologically stable self-dual gauge fields, i.e., vacua configurations that in spite of their masses do not deform the background geometry and are locally undetected by charged particles. We interpret these systems as describing boundary degrees of freedom of a self-dual Yang-Mills field in $2+2$ dimensions with mixed boundary conditions. Some of these fields correspond to Abrikosov-like vortices with an exponential damping in the direction penetrating into the bulk. We also propose generalizations of these ideas to higher dimensions and arbitrary p-form gauge connections.Comment: 18 page

Precisión lectora de palabras en lenguas de distinta consistencia

El objetivo de este estudio consiste en analizar las diferencias entre la lectura de palabras en alumnos ecuatorianos y argelinos en Educación Primaria. La muestra está formada por un grupo de 128 alumnos de una escuela de Ecuador y por otro grupo de 113 alumnos de una escuela de Argel, pertenecientes a una clase social media y sin necesidades educativas especiales. Los participantes fueron evaluados en precisión lectora de palabras en primero y segundo curso de Educación Primaria. Las palabras utilizadas en español fueron adaptadas al árabe, teniendo en cuenta la longitud y frecuencia de cada una de ellas en esta lengua. Se llevó a cabo un diseño factorial mixto 2x2, donde el factor intersujeto fue el tipo de lengua según la consistencia ortográfica (transparente y opaca) y el factor intrasujeto el nivel educativo (primero y segundo curso de educación primaria). Para la medida de la precisión lectora de palabras se registró el número de respuestas correctas. Los resultados del ANOVA de medidas repetidas en un factor muestran efectos significativos de los dos factores y de su interacción, encontrándose mejor precisión lectora de palabras en los niños de lengua árabe y en ambas lenguas en segundo curso de primaria. Estos resultados van en la línea de aquellos estudios que defienden las diferencias en la adquisición de la lectura en lenguas de distinta consistencia, pero no concuerdan con aquellos que apuntan que las lenguas opacas son más difíciles y tardías de aprender. Estas diferencias encontradas con estos estudios pueden ser debidas al grado de consistencia ortográfica de las lenguas analizadas. En conclusión, se resalta la necesidad de analizar las diferencias en otras edades y en otras medidas lectoras, controlando el grado de consistencia lingüística.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech