Some Properties of Domain Wall Solution in the Randall-Sundrum Model

Properties of the domain wall (kink) solution in the 5 dimensional Randall-Sundrum model are examined both {\it analytically} and {\it numerically}. The configuration is derived by the bulk Higgs mechanism. We focus on 1) the convergence property of the solution, 2) the stableness of the solution, 3) the non-singular property of the Riemann curvature, 4) the behaviours of the warp factor and the Higgs field. It is found that the bulk curvature changes the sign around the surface of the wall. We also present some {\it exact} solutions for two simple cases: a) the no potential case, b) the cosmological term dominated case. Both solutions have the (naked) curvature singularity. We can regard the domain wall solution as a singularity resolution of the exact solutions.Comment: Typographical error correction for publication. 16 pages, 4 figure

Estudio Preliminar Sobre La Decoloración Del Residual Líquido De La Producción De Papel Mediante Ozonización

Preliminarily, the relationship between Color Reduction (%RC), Total Suspended Solids concentration (SST), and as independent variable, the time of Ozone Oxidation Process, was evaluated with reference values of DQO of the black liquor adjusting its concentration from SST to 300 and 50mg/dm3. A batch reactor of 12,60dm3, an effective height of 3,2dm and an ozone generating device from SEFILTRA company (air flow of 2dm3/min, c(O3) of 9,50mg/dm3 with a O3(g) production 19mg/min) was used. The polynomic correlation was determined from 192 data sets with satisfactory adjustment level (R=0,92; p <0,001). Although, preliminarily, the DQO reduction (%RDQO) was not included in the polynomial relationship, it can be concluded that: a) The %RC and %RDQO is reduced when color and DQO increases from the ozonized sample at same time intervals; this reduction is greater when the SST levels of the ozonized sample increases. b) The %RC and %RDQO decrease when the SST level of the ozonized sample increases. c) Depending on the initial color, of the DQO and of the SST level of the sample, values from 10 to 53 %Rc were obtained after 10 min, and of 66 to 94 %Rc after 60 min

Coupled dark energy: Towards a general description of the dynamics

In dark energy models of scalar-field coupled to a barotropic perfect fluid, the existence of cosmological scaling solutions restricts the Lagrangian of the field \vp to p=X g(Xe^{\lambda \vp}), where X=-g^{\mu\nu} \partial_\mu \vp \partial_\nu \vp /2, $\lambda$ is a constant and $g$ is an arbitrary function. We derive general evolution equations in an autonomous form for this Lagrangian and investigate the stability of fixed points for several different dark energy models--(i) ordinary (phantom) field, (ii) dilatonic ghost condensate, and (iii) (phantom) tachyon. We find the existence of scalar-field dominant fixed points (\Omega_\vp=1) with an accelerated expansion in all models irrespective of the presence of the coupling $Q$ between dark energy and dark matter. These fixed points are always classically stable for a phantom field, implying that the universe is eventually dominated by the energy density of a scalar field if phantom is responsible for dark energy. When the equation of state w_\vp for the field \vp is larger than -1, we find that scaling solutions are stable if the scalar-field dominant solution is unstable, and vice versa. Therefore in this case the final attractor is either a scaling solution with constant \Omega_\vp satisfying 0<\Omega_\vp<1 or a scalar-field dominant solution with \Omega_\vp=1.Comment: 21 pages, 5 figures; minor clarifications added, typos corrected and references updated; final version to appear in JCA

Tendências de alterações na precipitação na área de atuação da Embrapa Tabuleiros Costeiros.

Além da região fisiográfica dos Tabuleiros Costeiros do Nordeste, a Área de Atuação da Embrapa Tabuleiros Costeiros (AETC) contempla áreas adjacentes, como a Baixada Litorânea e o Agreste, concentrando significativa parte das atividades agropecuárias da região com forte dependência da ocorrência de precipitações. Recentes relatórios do Painel Brasileiro de Mudanças Climáticas indicam tendências a significativas reduções nos volumes de chuva sobre a região Nordeste do Brasil (NEB), com impactos ainda desconhecidos sobre a sociedade e economia regional. Os índices de mudanças climáticas propostos pelo método RCLIMDEX foram aplicados às séries históricas de precipitação de 158 postos de chuva em quatro regiões da AETC, obtendo-se linhas de tendência e seus coeficientes angulares. Esses coeficientes foram padronizados e considerados como critério comparativo entre as regiões que compõem a AETC, gerando-se mapas que possibilitaram a análise espacial. Os índices revelaram diferenças significativas nas características das chuvas nas quatro regiões analisadas, com a maioria dos postos de chuva apresentando tendências de redução nos volumes precipitados. A Região 4, composta pelo Estado do Ceará e parte oeste do Rio Grande do Norte, apresentou índices com tendências mais críticas considerando a disponibilidade de chuvas. Apenas os índices R10mm, R20mm e PRECPTOT mostraram significância estatística nas tendências de redução para toda AETC. A análise espacial permitiu avaliar que postos com tendências de maior criticidade nos índices, do ponto de vista de disponibilidade de chuvas, situaram-se, em grande parte, na porção interior da AETC, próximos à zona de transição com o Semiárido do NEB

Noncommutative Black-Body Radiation: Implications On Cosmic Microwave Background

Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space noncommutativity on the Cosmic Microwave Background map is argued.Comment: 11 pages, no figs., LaTeX, accepted for Europhys. Let

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets