Correlations and synchronization in a Bose-Fermi mixture

We study a Bose-Fermi mixture within the framework of the mean-field theory, including three possible regimes for the fermionic species: fully polarized, BCS, and unitarity. Starting from the 3D description and using the variational approximation (VA), we derive 1D and 2D systems of equations, under the corresponding confining potentials. This method produces a pair of nonlinear Schr\"{o}dinger (NLS) equations coupled to algebraic equations for the transverse widths of the confined state. The equations incorporate interactions between atoms of the same species and between the species, assuming that the latter can be manipulated by means of the Feshbach resonance (FR). As an application, we explore spatial density correlations in the ground state (GS) between the species, concluding that they strongly depend on the sign and strength of the inter-species interaction. Also studied are the dynamics of the mixture in a vicinity of the GS and the corresponding spatiotemporal inter-species correlation. The correlations are strongly affected by the fermionic component, featuring the greatest variation in the unitary regime. Results produced by the VA are verified by comparison with full numerical solutions.Comment: Journal of Physics B: Atomic, Molecular and Optical Physics, in pres

Gravitino Dark Matter in Split Supersymmetry with Bilinear R-Parity Violation

In Split-SUSY with BRpV we show that the Gravitino DM solution is consistent with experimental evidence on its relic density and life time. We arrive at this conclusion by performing a complete numerical and algebraic study of the parameter space, including constraints from the recently determined Higgs mass, updated neutrino physics, and BBN constraints on NLSP decays. The Higgs mass requires a relatively low Split-SUSY mass scale, which is naturally smaller than usual values for reheating temperature, allowing the use of the standard expression for the relic density. We include restrictions from neutrino physics with three generations, and notice that the gravitino decay width depends on the atmospheric neutrino mass scale. We calculate the neutralino decay rate and find it consistent with BBN. We mention some implications on indirect DM searches.Comment: 35 pages, 7 figures. References added, typos corrected and experimental constraints updated. Some clarifications added in Section 2. Version to appear in EPJ

Gravity Effects on Neutrino Masses in Split Supersymmetry

The mass differences and mixing angles of neutrinos can neither be explained by R-Parity violating split supersymmetry nor by flavor blind quantum gravity alone. It is shown that combining both effects leads, within the allowed parameter range, to good agreement with the experimental results. The atmospheric mass is generated by supersymmetry through mixing between neutrinos and neutralinos, while the solar mass is generated by gravity through flavor blind dimension five operators. Maximal atmospheric mixing forces the tangent squared of the solar angle to be equal to 1/2. The scale of the quantum gravity operator is predicted within a 5% error, implying that the reduced Planck scale should lie around the GUT scale. In this way, the model is very predictive and can be tested at future experiments.Comment: 12 pages, 9 figures; In section 3 we extend our discussion about the definition of flavor basis in order to clarify in which basis the Gravity contributions are flavor blind. In the section 4 we add some words to explain why the Gravity contributions will not affect the charged lepton mass matrix; Finally we also fixed some minor typos regarding units or plot label

The variational reduction for low-dimensional Fermi gases and Bose - Fermi mixtures: A brief review

We present a summary of some recent theoretical results for matter-wave patterns in Fermi and Bose-Fermi degenerate gases, obtained in the framework of the quasi-mean-field approximation. We perform a dimensional reduction from the three-dimensional (3D) equations of motion to 2D and 1D effective equations. In both cases, comparison of the low-dimensional reductions to the full model is performed, showing very good agreement for ground-state solutions. Some complex dynamical regimes are reported too for the corresponding 1D systems.Comment: Condensed Matter, accepted. arXiv admin note: text overlap with arXiv:1502.0131

Witness gabriel graphs

We consider a generalization of the Gabriel graph, the witness Gabriel graph. Given a set of vertices P and a set of witness points W in the plane, there is an edge ab between two points of P in the witness Gabriel graph $GG^-$(P,W) if and only if the closed disk with diameter ab does not contain any witness point (besides possibly a and/or b). We study several properties of the witness Gabriel graph, both as a proximity graph and as a new tool in graph drawing.Postprint (published version

Villa CEREPEC-Chiguayante. Cooperativismo y vivienda colectiva en el Gran Concepción

El Área Metropolitana de Concepción (AMC) evidencia las huellas de la industria en su desarrollo urbano. Bajo el alero de las industrias estatales y de sus trabajadores, desde la segunda mitad del siglo XX se desarrollaron conjuntos habitacionales distanciados de las plantas industriales, que propusieron nuevos modos de desarrollo urbano para su época y lugar. Un caso relevante es el de la Cooperativa de Empleados Refinería de Petróleo Concepción (CEREPEC), en Chiguayante. Este trabajo registra parte de la evolución urbana de esta comuna, a través del análisis del conjunto habitacional, que se vio materializado por trabajadores de la Empresa Nacional del Petróleo (ENAP) bajo el modelo cooperativista. Los resultados evidencian tanto en el aporte fundacional a la construcción del espacio urbano de la “calle Manantiales”, como la forma en que el cooperativismo se materializó en el diseño urbano y el proyecto arquitectónico del conjunto CEREPEC. Destaca la relación empresa-trabajador-caja de ahorros, donde el trabajador asume el liderazgo y la empresa apoya la gestión, en un modelo muy distante del paternalismo industrial que construye con lógicas diferentes nuevas fracciones de ciudad. Se trata de un modelo de relevancia por cuanto los procesos participativos se constituyen en una demanda de gran actualidad, los que involucran las dinámicas de construcción y transformación de viviendas y barrios.A Área Metropolitana de Concepción (AMC) evidencia os traços da indústria em seu desenvolvimento urbano. Sob os auspícios das indústrias estatais e seus trabalhadores, desde a segunda metade do século XX, foram desenvolvidos conjuntos habitacionais distanciados das plantas industriais, que propuseram novos modos de desenvolvimento urbano para seu tempo e lugar. Um caso relevante é o da Cooperativa de Empregados da Refinaria de Petróleo Concepción (CEREPEC), em Chiguayante. Este trabalho registra parte da evolução urbana desta comuna, por meio da análise do conjunto habitacional, que foi materializado por trabalhadores da Empresa Nacional de Petróleo (ENAP) sob o modelo cooperativo. Os resultados mostram tanto a contribuição fundamental para a construção do espaço urbano da “Rua Manantiales”, quanto a forma como o cooperativismo se materializou no projeto urbano e arquitetônico do complexo CEREPEC. Destaca-se a relação empresa-trabalhador-banco, onde o trabalhador assume a liderança e a empresa apoia a gestão, num modelo muito distante do paternalismo industrial que constrói novas frações da cidade com lógicas diferentes. Este é um modelo relevante na medida em que os processos participativos são uma demanda altamente atual, envolvendo a dinâmica de construção e transformação de moradias e bairros.The Metropolitan Area of Concepción (AMC) has industrial traces in its urban development. Under the auspices of state industries and their workers, housing complexes were developed in the second half of the twentieth century, away from industrial plants, proposing new modes of urban development for the period and location. A case in question is the Cooperativa de Empleados Refinería de Petróleo Concepción (Concepcion Petrol Refinery Employees Cooperative or CEREPEC), in Chiguayante. This article records part of the urban evolution of this commune, through the analysis of a housing complex materialized by workers of the National Petroleum Company (ENAP) under the cooperative model. The results show both the foundational contribution in building the urban space of "Manantiales street", as well as the way cooperativism materialized in the urban design and the architectural project of the CEREPEC complex. The company-worker-savings bank relationship stands out, where the worker assumes the leadership and the company supports its management, in a model that is very distant from industrial paternalism, and which logically builds different new sectors in the city. It is a relevant model because participatory processes are in demand today, involving the dynamics of construction and transformation of houses and neighborhoods

Desarrollo de un Sistema de Informacion para el Registro de la Valoracion de Propiedades Agricolas

Resumen (Spanish, English)72 p.En general el valor de suelo es considerado un indicador de la situación general del sector agrícola. El tema del valor del suelo en Chile ha sido estudiado a través de un reducido número de trabajos, tener esta información actualizada es imprescindible para realizar estudios de rentabilidad de la agricultura. El presente estudio trata de la creación de una fuente de datos para el análisis del valor del suelo en la Zona Central Chile, para ello se presenta una descripción de la clase de información útil, la que es adecuada para el estudio de las diferentes variables que afectan el valor de la tierra y que además permite realizar análisis de la evolución de este. Los datos usados para el análisis proviene de los informes de tasación de la empresa el Tattersall Propiedades S.A. los cuales son detallados y abarcan el período de años desde 1982 a 1998. Por otra parte, dadas las ventajas que tiene el manejo de la información a través de un computador se diseñó y codificó un programa computacional que permite el manejo de la información y su análisis en aplicaciones estadísticas o planillas de cálculo. Además, se revisaron diferentes hipótesis respecto de algunas de las variables que afectan el valor del suelo agrícola como son la presencia de riego, plantaciones o construcciones, la relación entre el tamaño del predio y el valor unitario de este

Radiative Neutralino Decay in Split Supersymmetry

Radiative neutralino decay $\chi^0_2 -> \chi^0_1\gamma$ is studied in a Split Supersymmetric scenario, and compared with mSUGRA and MSSM. This 1-loop process has a transition amplitude which is often quite small, but has the advantage of providing a very clear and distinct signature: electromagnetic radiation plus missing energy. In Split Supersymmetry this radiative decay is in direct competition with the tree-level three-body decay $\chi^0_2 -> \chi^0_1 f\overline f$, and we obtain large values for the branching ratio $B(\chi^0_2 -> \chi^0_1\gamma)$ which can be close to unity in the region $M_2 \sim M_1$. Furthermore, the value for the radiative neutralino decay branching ratio has a strong dependence on the split supersymmetric scale $\widetilde{m}$, which is otherwise very difficult to infer from experimental observables.Comment: 15 pages and 10 figure

Vivienda y patrimonio industrial: los campamentos del petróleo en Magallanes

El descubrimiento de petróleo en la región de Magallanes detonó la aparición de infraestructuras y asentamientos humanos para la exploración, explotación, refinación y transporte de la producción. La historiografía local ha resaltado parcialmente el valor arquitectónico, paisajístico, histórico y social de un proceso singular de industrialización, dejando de lado las particularidades del hábitat colectivo asociado a la industria petrolera en la región austral. Este trabajo presenta la arquitectura de la vivienda de los campamentos del petróleo como una dimensión relevante en la construcción del patrimonio industrial asociado a la actividad petrolera de la región de Magallanes entre 1945 y 1972