37,733 research outputs found

    Quasi-homologous spherically symmetric branes and their symmetry breaking

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    We revisit the dynamical system based approach of spherically symmetric vacuum braneworlds, pointing out and studying the existence of a transcritical bifurcation as the dark pressure parameter changes its sign, we analyze some consequences of not discard the brane cosmological constant. For instance, it is noteworthy that the existence of an isothermal state equation between the dark fluid parameters cannot be obtained via the requirement of a quasi-homologous symmetry of the vacuum.Comment: 20 pages, 12 figures. To appear in EPJ

    Confinement in the 3-dimensional Gross-Neveu model

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    We consider the NN-components 3-dimensional massive Gross-Neveu model compactified in one spatial direction, the system being constrained to a slab of thickness LL. We derive a closed formula for the effective renormalized LL-dependent coupling constant in the large-N limit, using bag-model boundary conditions. For values of the fixed coupling constant in absence of boundaries λ≥λc≃19.16\lambda \geq \lambda_c \simeq 19.16, we obtain ultra-violet asymptotic freedom (for L→0L \to 0) and confinement for a length L(c)L^{(c)} such that 2.07m−1<L(c)≲2.82m−12.07 m^{-1} < L^{(c)} \lesssim 2.82 m^{-1}, mm being the fermionic mass. Taking for mm an average of the masses of the quarks composing the proton, we obtain a confining legth Lp(c)L^{(c)}_p which is comparable with an estimated proton diameter.Comment: Latex, 4 pages, 2 figures (one new), some changes in tex

    Solution for a local straight cosmic string in the braneworld gravity

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    In this work we deal with the spacetime shaped by a straight cosmic string, emerging from local gauge theories, in the braneworld gravity context. We search for physical consequences of string features due to the modified gravitational scenario encoded in the projected gravitational equations. It is shown that cosmic strings in braneworld gravity may present significant differences when compared to the general relativity predictions since its linear density is modified and the deficit angle produced by the cosmic string is attenuated. Furthermore, the existence of cosmic strings in that scenario requires a strong restriction to the braneworld tension: λ≥3×10−17\lambda \geq 3 \times 10^{-17}, in Planck units.Comment: 7 pages, 3 figure

    Static Domain Wall in the Braneworld gravity

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    In this paper we consider a static domain wall inside a 3-brane. Differently of the standard achievement obtained in General Relativity, the analysis performed here gives a consistency condition for the existence of static domain walls in a braneworld gravitational scenario. It is also shown the behavior of the domain wall gravitational field in the newtonian limit.Comment: 11 pages, no figures, accepted for publication in EPJ

    Realizing the supersymmetric inverse seesaw model in the framework of R-parity violation

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    If, on one hand, the inverse seesaw is the paradigm of TeV scale seesaw mechanism, on the other it is a challenge to find scenarios capable of realizing it. In this work we propose a scenario, based on the framework of R-parity violation, that realizes minimally the supersymmetric inverse seesaw mechanism. In it the energy scale parameters involved in the mechanism are recognized as the vacuum expectation values of the scalars that compose the singlet superfields N^C\hat N^C and S^\hat S. We develop also the scalar sector of the model and show that the Higgs mass receives a new tree-level contribution that, when combined with the standard contribution plus loop correction, is capable of attaining 125125GeV without resort to heavy stops.Comment: Minor modification of the text. Final version to be published in PL

    THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

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    This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 microns) with the Her- schel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed PACS (Photoconductor Array Camera and Spectrometer) spectra covering the 55-200 microns range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based inter- face (https://throes.cab.inta-csic.es/) and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS (Infrared Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars.Comment: 38 page

    Sistema de Monitoramento de Indicadores para a Produção Agrícola Sustentável.

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