28,337 research outputs found

    Dynamical analysis for a vector-like dark energy

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    In this paper we perform a dynamical analysis for a vector field as a candidate for the dark energy, in the presence of a barothropic fluid. The vector is one component of the so-called cosmic triad, which is a set of three identical copies of an abelian field pointing mutually in orthogonal directions. In order to generalize the analysis, we also assumed the interaction between dark energy and the barotropic fluid, with a phenomenological coupling. Both matter and dark energy eras can be successfully described by the critical points, indicating that the dynamical system theory is a viable tool to analyze asymptotic states of such cosmological models.Comment: 6 pages, 3 figures, version to appear in EPJ

    Cosmological tracking solution and the Super-Higgs mechanism

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    In this paper we argue that minimal supergravity with flat K\"ahler metric and a power-law superpotential can relate the Super-Higgs mechanism for the local spontaneous supersymmetry breaking and the cosmological tracking solution, leading in turn to a late-time accelerated expansion of the universe and alleviating the coincidence problem.Comment: 5 pages, 1 figure, minor corrections, to appear in EPJ

    Coupled dark energy: a dynamical analysis with complex scalar field

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    The dynamical analysis for coupled dark energy with dark matter is presented, where a complex scalar field is taken into account and it is considered in the presence of a barothropic fluid. We consider three dark energy candidates: quintessence, phantom and tachyon. The critical points are found and their stabilities analyzed, leading to the three cosmological eras (radiation, matter and dark energy), for a generic potential. The results presented here enlarge the previous analyses found in the literature.Comment: 9 pages, version accepted for publication in EPJC. arXiv admin note: text overlap with arXiv:1505.0324

    The international economic crisis and the colombian economy

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    The purpose of this research is to provide an approximation to the likely effects of the crisis on the Colombian economy and to the effectiveness of policy response. For this, the most relevant transmission channels and policy measures are simulated in the setting of a static computable general equilibrium model (CGE). The results obtained are interesting in their own right and are in line with what could be expected given the information available on the behavior of the Colombian economy. Furthermore, they call into question the effectiveness of governmental intervention as judged by its intended countercyclical effects.Crisis, Colombia, Applied General Equilibrium

    Tenth District economic developments

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    The Tenth District economy posted lower employment growth in 1997, marking the first time since 1988 that the district underperformed the nation. District agriculture posted solid gains in 1997, with big harvests and major improvements in the cattle industry. Overall, labor markets remained tight in most of the district, most likely limiting job growth in the region.> Gazel reviews the major economic developments in the district economy in 1997 and examines the outlook for 1998. The district economy is likely to grow moderately this year, nearly matching the 1997 pace. Tight labor markets throughout the district and slower growth at the national level will be major factors behind the slowdown. The region's economic growth in 1998 will be well-balanced. Manufacturing activity is likely to expand at the same pace as 1997, driven by gains in the production of durable goods. The service sector should grow moderately again in 1998, supported by solid performance in business and professional services. Retail and wholesale trade may be slowed by lower job and income growth across the district. Construction activity may weaken in 1998, although housing may improve somewhat. The district farm economy should remain relatively strong in 1998.Federal Reserve District, 10th

    Correctors for the Neumann problem in thin domains with locally periodic oscillatory structure

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    In this paper we are concerned with convergence of solutions of the Poisson equation with Neumann boundary conditions in a two-dimensional thin domain exhibiting highly oscillatory behavior in part of its boundary. We deal with the resonant case in which the height, amplitude and period of the oscillations are all of the same order which is given by a small parameter ϵ>0\epsilon > 0. Applying an appropriate corrector approach we get strong convergence when we replace the original solutions by a kind of first-order expansion through the Multiple-Scale Method.Comment: to appear in Quarterly of Applied Mathematic
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