Closed Spaces in Cosmology

This paper deals with two aspects of relativistic cosmologies with closed (compact and boundless) spatial sections. These spacetimes are based on the theory of General Relativity, and admit a foliation into space sections S(t), which are spacelike hypersurfaces satisfying the postulate of the closure of space: each S(t) is a 3-dimensional, closed Riemannian manifold. The discussed topics are: (1) A comparison, previously obtained, between Thurston's geometries and Bianchi-Kantowski-Sachs metrics for such 3-manifolds is here clarified and developed. (2) Some implications of global inhomogeneity for locally homogeneous 3-spaces of constant curvature are analyzed from an observational viewpoint.Comment: 20 pages, 6 figures, revised version of published paper. In version 2: several misprints corrected, 'redshifting' in figures improved. Version 3: a few style corrections; couple of paragraphs in subsection 2.4 rewritten. Version 4: figures 5 and 6 corrrecte

Proton-proton forward scattering at the LHC

Recently the TOTEM experiment at the LHC has released measurements at $\sqrt{s} = 13$ TeV of the proton-proton total cross section, $\sigma_{tot}$, and the ratio of the real to imaginary parts of the forward elastic amplitude, $\rho$. Since then an intense debate on the $C$-parity asymptotic nature of the scattering amplitude was initiated. We examine the proton-proton and the antiproton-proton forward data above 10 GeV in the context of an eikonal QCD-based model, where nonperturbative effects are readily included via a QCD effective charge. We show that, despite an overall satisfactory description of the forward data is obtained by a model in which the scattering amplitude is dominated by only crossing-even elastic terms, there is evidence that the introduction of a crossing-odd term may improve the agreement with the measurements of $\rho$ at $\sqrt{s} = 13$ TeV. In the Regge language the dominant even(odd)-under-crossing object is the so called Pomeron (Odderon).Comment: 5 pages, 2 figures, 1 table. Phenomenological approach revised, results and conclusions changed, suggesting now the presence of Odderon effects in forward scattering (once confirmed the TOTEM data at 13 TeV

Uma nova etapa da Instrução Normativa n° 51: a Região Centro-Sul.

Após a verificação da insuficiente qualidade do leite produzido no País, a Secretaria de Defesa Agropecuária (SDA/Mapa) publicou a Instrução Normativa nº 51 em setembro de 2002 (IN nº 51/2002), cujas novas exigências entraram em vigor, na Região Centro-Sul, em 1º/7/2005. Esse normativo estabelece requisitos mínimos de qualidade para os leites tipo A, B e C, para o leite cru refrigerado e pasteurizado, além de dispor normas para a coleta a granel da matériaprima. Para as regiões Norte e Nordeste, essas exigências só passarão a ser obrigatórias a partir de 1º/7/2007. Trata-se de uma iniciativa que deverá incentivar a melhoria da qualidade do leite inspecionado por meio da aplicação de testes de qualidade mais rigorosos. Estão previstas, com base em um calendário diferenciado por região, etapas progressivas para a melhoria da qualidade, as quais se estendem de 2002 a 2011 para a Região Centro-Sul (Sul, Sudeste e Centro-Oeste), e de 2002 a 2012 para as regiões Norte e Nordeste. A pequena produção leiteira deverá adequar-se às novas disposições normativas mediante a sua organização em associações, bem como com a disponibilização de tanques comunitários de resfriamento

Preliminary Results on the Empirical Applicability of the Tsallis Distribution in Elastic Hadron Scattering

We show that the proton-proton elastic differential cross section data at dip position and beyond can be quite well described by a parametrization based on the Tsallis distribution, with only five free fit parameters. Extrapolation of the results obtained at 7 TeV to large momentum transfer, suggests that hadrons may not behave as a black-disk at the asymptotic energy region.Comment: 3 pages, 1 figure, version matching proceedings style, XII Hadron Physics, 2012, AIP Proc. Con