45 research outputs found

    Newtonian gravity and resonance on de-Sitter branes

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    A dS brane on the boundary between two five-dimensional spacetimes is determined. We consider asymmetric scenarios with AdS5{}_5 vacua at each side of the dS brane; and as a result, a resonant mode inside of the spectrum of the gravitational fluctuations is found. We analyze the deviations to the Newton potential generated by the gravitational excitations, finding that, for scenarios with large values of the cosmological constants, the contribution of the resonant mode is exponentially suppressed. However, when one of the vacua is null, the resonant mode belongs to the light states set of the gravitational fluctuations and five-dimensional gravity is recovered on the dS brane.Comment: 6 pages, 2 figure

    Close to the edge: hierarchy in a double braneworld

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    We show that the hierarchy between the Planck and the weak scales can follow from the tendency of gravitons and fermions to localize at different edges of a thick double wall embedded in an AdS5AdS_5 spacetime without reflection symmetry. This double wall is a stable BPS thick-wall solution with two sub-walls located at its edges; fermions are coupled to the scalar field through Yukawa interactions, but the the lack of reflection symmetry forces them to be localized in one of the sub-walls. We show that the graviton zero-mode wavefunction is suppressed in the fermion edge by an exponential function of the distance between the sub-walls, and that the massive modes decouple so that Newtonian gravity is recuperated.Comment: Some typos corrected, references adde

    Gauge field localization on brane worlds

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    We consider the effects of spacetime curvature and brane thickness on the localization of gauge fields on a brane via kinetic terms induced by localized fermions. We find that in a warped geometry with and infinitely thin brane, both the infrared and the ultraviolet behavior of the electromagnetic propagator are affected, providing a more stringent bound on the brane's tension than that coming from the requirement of four-dimensional gravity on the brane. On the other hand, for a thick wall in a flat spacetime, where the fermions are localized by means of a Yukawa coupling, we find that 4-dimensional electromagnetism is recovered in a region bounded from above by the same critical distance appearing in the thin case, but also from below by a new scale related to the brane's thickness and the electromagnetic couplings.Comment: 7 page

    Diseño del sistema de gestión de seguridad y salud en base al modelo Ecuador para su futura implementación en la empresa Ecoroses S.A.

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    Ecoroses SA is dedicated to cultivating, producing and exporting roses for 12 years, it currently has 206 workers, of whom 175 represents the workforce of the company, distributed in the areas of cultivation, post harvest, irrigation and maintenance. Being considered the company as "high risk" one and having over 100 employees, the Ecuadorian legal standards required the implementation of a Safety Management System and Health, this system should be led by a trained technician in this area.Ecoroses S.A. se dedica a cultivar, producir y exportar rosas desde hace 12 años, para ello cuenta actualmente con 206 trabajadores, de los cuales 175 representan la mano de obra productiva de la empresa, distribuidos en las áreas de cultivo, postcosecha, mantenimiento y riego. Al ser considera la empresa como de “alto riesgo” y por tener más de 100 empleados, la normativa legal ecuatoriana exige que se implemente un Sistema de Gestión de Seguridad y Salud, este sistema debe estar liderado por un técnico especializado en esta materia

    Self-gravitating domain walls and the thin-wall limit

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    We analyse the distributional thin wall limit of self gravitating scalar field configurations representing thick domain wall geometries. We show that thick wall solutions can be generated by appropiate scaling of the thin wall ones, and obtain an exact solution for a domain wall that interpolates between AdS_4 asymptotic vacua and has a well-defined thin wall limit.Solutions representing scalar field configurations obtained via the same scaling but that do not have a thin wall limit are also presented.Comment: 10 pages, revte
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