Black string corrections in variable tension braneworld scenarios

Braneworld models with variable tension are investigated, and the corrections on the black string horizon along the extra dimension are provided. Such corrections are encrypted in additional terms involving the covariant derivatives of the variable tension on the brane, providing profound consequences concerning the black string horizon variation along the extra dimension, near the brane. The black string horizon behavior is shown to be drastically modified by the terms corrected by the brane variable tension. In particular, a model motivated by the phenomenological interesting case regarding Eotvos branes is investigated. It forthwith provides further physical features regarding variable tension braneworld scenarios, heretofore concealed in all previous analysis in the literature. All precedent analysis considered uniquely the expansion of the metric up to the second order along the extra dimension, what is able to evince solely the brane variable tension absolute value. Notwithstanding, the expansion terms aftermath, further accomplished in this paper from the third order on, elicits the successive covariant derivatives of the brane variable tension, and their respective coupling with the extrinsic curvature, the Weyl tensor, and the Riemann and Ricci tensors, as well as the scalar curvature. Such additional terms are shown to provide sudden modifications in the black string horizon in a variable tension braneworld scenarioComment: 12 pages, 5 figures, accepted in PR

WebGis como ferramenta de gestão agropecuária na Embrapa Pecuária Sul.

Apsul América

Capim corrente: opção para criação animal a pasto no semiárido.

bitstream/item/115055/1/midia-Capim.pd

False Vacuum Transitions - Analytical Solutions and Decay Rate Values

In this work we show a class of oscillating configurations for the evolution of the domain walls in Euclidean space. The solutions are obtained analytically. Phase transitions are achieved from the associated fluctuation determinant, by the decay rates of the false vacuum.Comment: 6 pages, improved to match the final version to appear in EP

The effects of systemic banking crises in the inter-war period

This paper examines the time-profile of the impact of systemic banking crises on GDP and industrial production using a panel of 24 countries over the inter-war period and compares this to the post-war experience of these countries. We show that banking crises have effects that induce medium-term adjustments on economies. Focusing on an eight-year horizon, it is clear that the negative effects of systemic banking crises last over the entirety of this time-horizon. The effect has been identified for GDP and industrial production. The adverse effect on the industrial sector stands out as being substantially larger in magnitude relative to the macroeconomic effect. Comparing the results across long-run historical periods for the same selection of countries and variables identifies some differences that stand out: the short term macroeconomic impact effects are much larger in the post-war period, suggesting that the propagation channels of shocks operate at a faster pace in the more recent period. Moreover, the time-profile of effects differs, suggesting that modern policies may be modulating the temporal shape of the response to banking crises shocks. However, the broad magnitude of the adverse effect of banking crises remains comparable across these time periods

Notes on the Two-brane Model with Variable Tension

Motivated by possible extensions of the braneworld models with two branes, we investigate some consequences of a variable brane tension using the well established results on consistency conditions. By a slight modification of the usual stress-tensor used in order to derive the braneworld sum rules, we find out some important constraints obeyed by time dependent brane tensions. In particular it is shown that the tensions of two Randall-Sundrum like branes obeying, at the same time, an Eotvos law, aggravate the fine tuning problem. Also, it is shown that if the hidden brane tension obeys an Eotvos law, then the visible brane has a mixed behavior allowing a bouncing-like period at early times while it is dominated by an Eotvos law nowadays. To finalize, we discuss some qualitative characteristics which may arise in the scope of dynamical brane tensions, as anisotropic background and branons production.Comment: 7 pages, 1 figure, accepted for publication in Physical Review