Gravitational Collapse of Dust with a Cosmological Constant

The recent analysis of Markovic and Shapiro on the effect of a cosmological constant on the evolution of a spherically symmetric homogeneous dust ball is extended to include the inhomogeneous and degenerate cases. The histories are shown by way of effective potential and Penrose-Carter diagrams.Comment: 2 pages, 2 figures (png), revtex. To appear in Phys. Rev.

The first 62 AGN observed with SDSS-IV MaNGA - IV: gas excitation and star-formation rate distributions

We present maps of the ionized gas flux distributions, excitation, star-formation rate SFR, surface mass density $\Sigma_{H+}$, and obtain total values of SFR and ionized gas masses {\it M} for 62 Active Galactic Nuclei (AGN) observed with SDSS-IV MaNGA and compare them with those of a control sample of 112 non-active galaxies. The most luminous AGN -- with L(\rm{[OIII]}\lambda 5007) \ge 3.8\times 10^{40}\,\mbox{erg}\,\mbox{s}^{-1}, and those hosted by earlier-type galaxies are dominated by Seyfert excitation within 0.2 effective radius $R_e$ from the nucleus, surrounded by LINER excitation or transition regions, while the less luminous and hosted by later-type galaxies show equally frequent LINER and Seyfert excitation within $0.2\,R_e$. The extent $R$ of the region ionized by the AGN follows the relation $R\propto\,L(\rm{[OIII]})^{0.5}$ -- as in the case of the Broad-Line Region. The SFR distribution over the region ionized by hot stars is similar for AGN and controls, while the integrated SFR -- in the range $10^{-3}-10$\,M$_\odot$\,yr$^{-1}$ is also similar for the late-type sub-sample, but higher in the AGN for 75\% of the early-type sub-sample. We thus conclude that there is no signature of AGN quenching star formation in the body of the galaxy in our sample. We also find that 66\% of the AGN have higher ionized gas masses $M$ than the controls -- in the range 10$^5-3\times10^7$\,M$_\odot$ -- while 75\% of the AGN have higher $\Sigma_{H+}$ within $0.2\,R_e$ than the control galaxies

Rendimento e eficiência da fermentação alcoólica na produção de hidromel.

bitstream/CPAP-2009-09/56928/1/BP84.pd

Tecnologia de produção de vinagre de mel.

Com a perspectiva de diversificação dos produtos derivados do mel, este trabalho teve como finalidade avaliar a produção de vinagre de mel de abelhas africanizadas (Apis mellifera L.). A produção do vinagre foi realizada através da fermentação acética de hidromel com teor alcoólico de 8% (v/v), obtido a partir de um mosto com 17,11% (m/v) de açúcares totais. A fermentação acética foi realizada pelo método rápido, em fermentador vertical com capacidade de 15 litros, utilizando vinagre forte não pasteurizado como inóculo, por 72 horas. Durante esta fermentação foram monitoradas as temperaturas interna (fermentador) e ambiente. O vinagre obtido apresentou acidez em torno de 9% e teor alcoólico em torno de 1% (v/v). O rendimento da fermentação acética foi entre 91,2 e 97,17%. O produto final foi diluído de acordo com a legislação brasileira (4,0% de acidez) e analisado sensorialmente, demonstrando ser de boa aceitabilidade Os teores de álcool etílico, ácido acético, resíduo mineral fixo e resíduo seco a 105oC foram de 0,32%; 4,2%; 0,05% e 1,76%, respectivamente. A análise microscópica revelou ausência de sujidades, larvas e parasitas.bitstream/CPAP-2009-09/57063/1/BP86.pd

The first 62 AGN observed with SDSS-IV MaNGA -- III: stellar and gas kinematics

We investigate the effects of Active Galactic Nuclei (AGN) on the gas kinematics of their host galaxies, using MaNGA data for a sample of 62 AGN hosts and 109 control galaxies (inactive galaxies). We compare orientation of the line of nodes (kinematic Position Angle - PA) measured from the gas and stellar velocity fields for the two samples. We found that AGN hosts and control galaxies display similar kinematic PA offsets between gas and stars. However, we note that AGN have larger fractional velocity dispersion $\sigma$ differences between gas and stars [$\sigma_{frac}=(\sigma_{\rm gas}-\sigma_{stars})/\sigma_{\rm stars}$] when compared to their controls, as obtained from the velocity dispersion values of the central (nuclear) pixel (2.5" diameter). The AGN have a median value of $\sigma_{\rm frac}$ of $_{\rm AGN}=0.04$, while the the median value for the control galaxies is $_{\rm CTR}=-0.23$. 75% of the AGN show $\sigma_{frac}>-0.13$, while 75% of the normal galaxies show $\sigma_{\rm frac}<-0.04$, thus we suggest that the parameter $\sigma_{\rm frac}$ can be used as an indicative of AGN activity. We find a correlation between the [OIII]$\lambda$5007 luminosity and $\sigma_{frac}$ for our sample. Our main conclusion is that the AGN already observed with MaNGA are not powerful enough to produce important outflows at galactic scales, but at 1-2 kpc scales, AGN feedback signatures are always present on their host galaxies.Comment: 19 pages, 8 figures, published in MNRA

Dimensionally continued Oppenheimer-Snyder gravitational collapse. I - solutions in even dimensions

The extension of the general relativity theory to higher dimensions, so that the field equations for the metric remain of second order, is done through the Lovelock action. This action can also be interpreted as the dimensionally continued Euler characteristics of lower dimensions. The theory has many constant coefficients apparently without any physical meaning. However, it is possible, in a natural way, to reduce to two (the cosmological and Newton's constant) these several arbitrary coefficients, yielding a restricted Lovelock gravity. In this process one separates theories in even dimensions from theories in odd dimensions. These theories have static black hole solutions. In general relativity, black holes appear as the final state of gravitational collapse. In this work, gravitational collapse of a regular dust fluid in even dimensional restricted Lovelock gravity is studied. It is found that black holes emerge as the final state for these regular initial conditions.Comment: Late

On the dual equivalence of the Born-Infeld-Chern-Simons model coupled to dynamical U(1) charged matter

We study the equivalence between a nonlinear self-dual model (NSD) with the Born-Infeld-Chern-Simons (BICS) models using an iterative gauge embedding procedure that produces the duality mapping, including the case where the NSD model is minimally coupled to dynamical, U(1) charged fermionic matter. The duality mapping introduces a current-current interaction term while at the same time the minimal coupling of the original nonlinear self-dual model is replaced by a non-minimal magnetic like coupling in the BICS side.Comment: RevteX file, 6 pages, no figures; acknowledgements corrected, version to appear in Physics Letters

Dual equivalence in models with higher-order derivatives

We introduce a class of higher-order derivative models in (2,1) space-time dimensions. The models are described by a vector field, and contain a Proca-like mass term which prevents gauge invariance. We use the gauge embedding procedure to generate another class of higher-order derivative models, gauge-invariant and dual to the former class. We show that the results are valid in arbitrary (d,1) space-time dimensions when one discards the Chern-Simons and Chern-Simons-like terms. We also investigate duality at the quantum level, and we show that it is preserved in the quantum scenario. Other results include investigations concerning the gauge embedding approach when the vector field couples with fermionic matter, and when one adds nonlinearity.Comment: RevTex4, 14 pages; new version includes duality at the quantum level, and new references. To be published in J. Phys.

Gravitational collapse to toroidal, cylindrical and planar black holes

Gravitational collapse of non-spherical symmetric matter leads inevitably to non-static external spacetimes. It is shown here that gravitational collapse of matter with toroidal topology in a toroidal anti-de Sitter background proceeds to form a toroidal black hole. According to the analytical model presented, the collapsing matter absorbs energy in the form of radiation (be it scalar, neutrinos, electromagnetic, or gravitational) from the exterior spacetime. Upon decompactification of one or two coordinates of the torus one gets collapsing solutions of cylindrical or planar matter onto black strings or black membranes, respectively. The results have implications on the hoop conjecture.Comment: 6 pages, Revtex, modifications in the title and in the interpretation of some results, to appear in Physical Review