Stability analysis of 5D gravitational solutions with N bulk scalar fields

We study the stability of 5D gravitational solutions containing an arbitrary number of scalar fields. A closed set of equations is derived which governs the background and perturbations of N scalar fields and the metric, for arbitrary bulk and boundary scalar potentials. In particular the effect of the energy-momentum tensor of the scalar fields on the geometry is fully taken into account, together with all the perturbations of the system. The equations are explicitly written as an eigenvalue problem, which can be readily solved to determine the stability of the system and obtain the properties of the fluctuations, such as masses and couplings. As an example, we study a dynamical soft-wall model with two bulk scalar fields used to model the hadron spectrum of QCD and the Higgs sector of electroweak physics. It is shown that there are no tachyonic modes, and that there is a (radion) mode whose mass is suppressed by a large logarithm compared to that of the other Kaluza-Klein modes.Comment: 15 pages, 5 figures. v2: refs adde

Programa de melhoramento genético do feijoeiro comum da Embrapa Arroz e Feijão.

O programa de melhoramento genético do feijoeiro comum da Embrapa Arroz e Feijão definiu as característica nutricional com uma das prioridades de pesquisa e desenvolvimento da cultura. Nesse escopo, o projeto biofortificação do feijoeiro comum identificou germoplasma-fontes com maiores teores de ferro e zinco e formou populações para iniciar seleção nas gerações segregantes

Dangerous Angular KK/Glueball Relics in String Theory Cosmology

The presence of Kaluza-Klein particles in the universe is a potential manifestation of string theory cosmology. In general, they can be present in the high temperature bath of the early universe. In particular examples, string theory inflation often ends with brane-antibrane annihilation followed by the energy cascading through massive closed string loops to KK modes which then decay into lighter standard model particles. However, massive KK modes in the early universe may become dangerous cosmological relics if the inner manifold contains warped throat(s) with approximate isometries. In the complimentary picture, in the AdS/CFT dual gauge theory with extra symmetries, massive glueballs of various spins become the dangerous cosmological relics. The decay of these angular KK modes/glueballs, located around the tip of the throat, is caused by isometry breaking which results from gluing the throat to the compact CY manifold. We address the problem of these angular KK particles/glueballs, studying their interactions and decay channels, from the theory side, and the resulting cosmological constraints on the warped compactification parameters, from the phenomenology side. The abundance and decay time of the long-lived non-relativistic angular KK modes depend strongly on the parameters of the warped geometry, so that observational constraints rule out a significant fraction of the parameter space. In particular, the coupling of the angular KK particles can be weaker than gravitational.Comment: 58 pages, 11 figures, published versio

Preheating with Trilinear Interactions: Tachyonic Resonance

We investigate the effects of bosonic trilinear interactions in preheating after chaotic inflation. A trilinear interaction term allows for the complete decay of the massive inflaton particles, which is necessary for the transition to radiation domination. We found that typically the trilinear term is subdominant during early stages of preheating, but it actually amplifies parametric resonance driven by the four-legs interaction. In cases where the trilinear term does dominate during preheating, the process occurs through periodic tachyonic amplifications with resonance effects, which is so effective that preheating completes within a few inflaton oscillations. We develop an analytic theory of this process, which we call tachyonic resonance. We also study numerically the influence of trilinear interactions on the dynamics after preheating. The trilinear term eventually comes to dominate after preheating, leading to faster rescattering and thermalization than could occur without it. Finally, we investigate the role of non-renormalizable interaction terms during preheating. We find that if they are present they generally dominate (while still in a controllable regime) in chaotic inflation models. Preheating due to these terms proceeds through a modified form of tachyonic resonance.Comment: 19 pages, 10 figures, refs added, published versio

Fatores da tolerância do feijoeiro à seca.

Com este trabalho, objetivou-se estudar fatores da tolerância de genótipos de feijoeiro comum à seca

Cultivares de feijoeiro comum para o Estado de MInas Gerais.

As novas cultivares de feijoeiro comum recomendadas para cultivo em Minas Gerais vêm proporcionar aos agricultores várias opções quanto ao tipo de grão, resistência à doenças, porte da planta e precocidade, entre outras características. A escolha deve recair sobre aquela que melhor atenda às necessidades, condições de cultivo e oportunidade de comercialização.bitstream/CNPAF/22245/1/circ_65.pd

Emergent Gravity from a Mass Deformation in Warped Spacetime

We consider a deformation of five-dimensional warped gravity with bulk and boundary mass terms to quadratic order in the action. We show that massless zero modes occur for special choices of the masses. The tensor zero mode is a smooth deformation of the Randall-Sundrum graviton wavefunction and can be localized anywhere in the bulk. There is also a vector zero mode with similar localization properties, which is decoupled from conserved sources at tree level. Interestingly, there are no scalar modes, and the model is ghost-free at the linearized level. When the tensor zero mode is localized near the IR brane, the dual interpretation is a composite graviton describing an emergent (induced) theory of gravity at the IR scale. In this case Newton's law of gravity changes to a new power law below the millimeter scale, with an exponent that can even be irrational.Comment: 44 pages, 3 figure

Sistema de cultivo e custo de produção de feijoeiro comum em Primavera do Leste (MT), na safra 2004/2005.

O presente trabalho teve como objetivos: (a) caracterizar o sistema de cultivo de feijoeiro comum praticado em Primavera do Leste (MT); e (b) estimar o custo de produção de feijoeiro comum deste sistema de cultivo na safra 2004/2005.bitstream/CNPAF/23590/1/comt_101.pd

Feijão na economia nacional.

Este trabalho apresenta um panorama do agronegócio brasileiro situando o feijão neste segmento da economia nacional. Aborda, além dos aspectos socioeconômicos e técnicos, seus reflexos na produção, comercialização, distribuição e no consumo desta leguminosa.bitstream/CNPAF/19419/1/doc_135.pd