A Unified Algebraic Approach to Few and Many-Body Correlated Systems

The present article is an extended version of the paper {\it Phys. Rev.} {\bf B 59}, R2490 (1999), where, we have established the equivalence of the Calogero-Sutherland model to decoupled oscillators. Here, we first employ the same approach for finding the eigenstates of a large class of Hamiltonians, dealing with correlated systems. A number of few and many-body interacting models are studied and the relationship between their respective Hilbert spaces, with that of oscillators, is found. This connection is then used to obtain the spectrum generating algebras for these systems and make an algebraic statement about correlated systems. The procedure to generate new solvable interacting models is outlined. We then point out the inadequacies of the present technique and make use of a novel method for solving linear differential equations to diagonalize the Sutherland model and establish a precise connection between this correlated system's wave functions, with those of the free particles on a circle. In the process, we obtain a new expression for the Jack polynomials. In two dimensions, we analyze the Hamiltonian having Laughlin wave function as the ground-state and point out the natural emergence of the underlying linear $W_{1+\infty}$ symmetry in this approach.Comment: 18 pages, Revtex format, To appear in Physical Review

Using the set point concept to allow water distribution system skeletonization preserving water quality constraints

[EN] Water distribution networks were included in the catalogue of critical infrastructures by different institutions as the European Council. One of the vulnerabilities of a water distribution networks consists of the contamination due to accidental or provoked events. Therefore, it is increasingly common to develop water quality models which allow the study of these threats. Many hydraulic models use algorithms with a high computational cost. Therefore, any strategy to accelerate these algorithms is an important contribution to the problem. This paper proposes a method to simplify branched areas of the network without losing information regarding water quality.This article has been possible inside the actions developed by the researchers of UPV involved in the project “Mejora de las técnicas de llenado y operación de redes de abastecimiento de agua (OPERAGUA)”. The number reference of the project is DPI2009-13674.Martínez-Solano, FJ.; Iglesias Rey, PL.; Mora Meliá, D.; Fuertes Miquel, VS. (2014). Using the set point concept to allow water distribution system skeletonization preserving water quality constraints. Procedia Engineering. 2014(89):213-219. https://doi.org/10.1016/j.proeng.2014.11.179S21321920148

Remote sensing of lunar aureole with a sky camera: Adding information in the nocturnal retrieval of aerosol properties with GRASP code

The use of sky cameras for nocturnal aerosol characterization is discussed in this study. Two sky cameras are configured to take High Dynamic Range (HDR) images at Granada and Valladolid (Spain). Some properties of the cameras, like effective wavelengths, sky coordinates of each pixel and pixel sensitivity, are characterized. After that, normalized camera radiances at lunar almucantar points (up to 20° in azimuth from the Moon) are obtained at three effective wavelengths from the HDR images. These normalized radiances are compared in different case studies to simulations fed with AERONET aerosol information, giving satisfactory results. The obtained uncertainty of normalized camera radiances is around 10% at 533 nm and 608 nm and 14% for 469 nm. Normalized camera radiances and six spectral aerosol optical depth values (obtained from lunar photometry) are used as input in GRASP code (Generalized Retrieval of Aerosol and Surface Properties) to retrieve aerosol properties for a dust episode over Valladolid. The retrieved aerosol properties (refractive indices, fraction of spherical particles and size distribution parameters) are in agreement with the nearest diurnal AERONET products. The calculated GRASP retrieval at night time shows an increase in coarse mode concentration along the night, while fine mode properties remained constant.This work was supported by the Andalusia Regional Government (project P12-RNM-2409) and by the “Consejería de Educación, Junta de Castilla y León” (project VA100U14).Spanish Ministry of Economy and Competitiveness and FEDER funds under the projects CGL2013-45410-R, CMT2015-66742-R, CGL2016-81092-R.“Juan de la Cierva-Formación” program (FJCI-2014-22052).European Union's Horizon 2020 research and innovation programme through project ACTRIS-2 (grant agreement No 654109)

Una adaptación de un mito gnóstico con intención formativa en la antigüedad tardía: los demonios del capítulo 65 de la Vita Antonii de Atanasio de Alejandría

The aim of this work is to deepen into Late Antique Christian demonology, and to analyze an ambiguous passage in the Vita Antonii by Athanasius of Alexandria that describes the ascension of Antonius� soul to heavens and its encounter with such terrible �beings�. The author departs from J. Daniélou�s works on air powers and its role in some variants of the Gnostic myth about the ascent of the soul through the different heavens. Thereupon, he delves into the passage providing different textual parallels. He finishes joining D. Brakkes� perspectives on Athanasius ascetic theories to defend that these �beings� might be identified with the Gnostic Archons, term silenced by the bishop due to its heretical links in his efforts to inculcate the believers with the idea of that the only requirement to achieve salvation was a virtuous moral behavior.Buscando profundizar en la demonología cristiana tardoantigua, el trabajo analiza un ambiguo pasaje de la Vita Antonii de Atanasio de Alejandría donde se narra la ascensión del alma de Antonio a los cielos y su encuentro con unos seres �terribles�. El autor parte de los trabajos de J. Daniélou sobre las potencias aéreas y su papel en las distintas variantes del mito gnóstico del ascenso del alma a través de los diferentes cielos. A partir de ahí, el autor profundiza en el análisis del pasaje, aportando diversos paralelos textuales. Termina adhiriéndose a las perspectivas de D. Brakke sobre las teorías ascéticas de Atanasio para defender finalmente que dichos �seres� podrían identificarse con los «arcontes», término de connotaciones heterodoxas que el obispo habría silenciado en sus esfuerzos para inculcar en los fieles la idea de que lo realmente necesario para alcanzar la salvación era un comportamiento moral virtuoso

Double Coverings Of Hyperelliptic Real Algebraic Curves

We consider double and (possibly) branched coverings : X ! X0 between real algebraic curves where X is hyperelliptic. We are interested in the topology of such coverings and also in describing them in terms of algebraic equations. In this article we completely solve these two problems. We first analyse the topological features and ramification data of such coverings. Second, for each isomorphism class of these coverings we then describe a representative, with defining polynomial equations for X and for X0, a formula for the involution that generates the coveri transformation group, and a rational formula forng the covering projection : X ! X0

Adaptation of the human gut microbiota metabolic network during the first year after birth

Predicting the metabolic behavior of the human gut microbiota in different contexts is one of the most promising areas of constraint-based modeling. Recently, we presented a supra-organismal approach to build context-specific metabolic networks of bacterial communities using functional and taxonomic assignments of meta-omics data. In this work, this algorithm is applied to elucidate the metabolic changes induced over the first year after birth in the gut microbiota of a cohort of Spanish infants. We used metagenomics data of fecal samples and nutritional data of 13 infants at five time points. The resulting networks for each time point were analyzed, finding significant alterations once solid food is introduced in the diet. Our work shows that solid food leads to a different pattern of output metabolites that can be potentially released from the gut microbiota to the host. Experimental validation is presented for ferulate, a neuroprotective metabolite involved in the gut-brain axis

Optical absorption of defect chalcopyrite and defect stannite ZnGa2Se4 under high pressure

Optical absorption measurements at high pressure have been performed in two phases of the ordered-vacancy compound (OVC) ZnGa2Se4: defect stannite (DS) and defect chalcopyrite (DC). The direct bandgap energy of both phases exhibits a non-linear pressure dependence with a blueshift up to 10 GPa and a redshift at higher pressures. We discuss the different behavior of both phases in these two pressure ranges in relation to the pressure-induced order-disorder processes taking place at cation sites. Measurements performed in both phases on downstroke after increasing pressure to 22 GPa show that the direct bandgap energy of the recovered samples at room pressure was 0.35 eV smaller than that of the original samples. These results evidence that different disordered phases are formed on decreasing pressure, depending on the cation disorder already present in the original samples. In particular, we attribute the recovered samples from the original DC and DS phases to disordered CuAu (DCA) and disordered zincblende (DZ) phases, respectively. The decrease of the direct bandgap energy and its pressure coefficient on increasing disorder in the four measured phases are explained. In summary, this combined experimental and theoretical work on two phases (DC and DS) of the same compound has allowed us to show that the optical properties of both phases show a similar behavior under compression because irreversible pressure-induced order-disorder processes occur in all adamantine OVCs irrespective of the initial crystalline structure