On the space of generalized fluxes for loop quantum gravity

We show that the space of generalized fluxes - momentum space - for loop quantum gravity cannot be constructed by Fourier transforming the projective limit construction of the space of generalized connections - position space - due to the non-abelianess of the gauge group SU(2). From the abelianization of SU(2), U(1)^3, we learn that the space of generalized fluxes turns out to be an inductive limit, and we determine the consistency conditions the fluxes should satisfy under coarse-graining of the underlying graphs. We comment on the applications to loop quantum cosmology, in particular, how the characterization of the Bohr compactification of the real line as a projective limit opens the way for a similar analysis for LQC

Variações anuais na produção de frutos de castanha-da-amazônia no sul do Amapá.

A castanha-da-amazônia é uma espécie típica da região. Além da sua importância para o setor alimentício e de cosméticos, também é considerada alimento funcional e pode prevenir algumas enfermidades. Com isso, tem aumentado a demanda pela produção de castanha. Todavia, estudos sobre a variação anual na oferta de castanha ainda são incipientes. Assim, o objetivo do presente estudo foi avaliar a produção de frutos da castanheira, ao longo dos anos e em diferentes ambientes no sul do Amapá

Danos de Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae) em castanheiras na reserva extrativista do rio Cajari, AP.

Resumo 1

Monitoramento da produção de frutos da castanheira-da-amazônia no sul do Amapá.

A castanheira (Bertholletia excelsa Bonpl.) é nativa da Amazônia, fonte de alimentação e renda para muitos agroextrativistas, tendo ganhado notoriedade na indústria cosmética e alimentícia. A produção de seus frutos (ouriços) pode variar ao longo dos anos, em função do ambiente e de atributos das próprias castanheiras. Dessa forma, objetivou-se analisar a variação da produção de frutos em ambientes florestais distintos e verificar a relação da distribuição diamétrica com a produção

Quantum metastability in a class of moving potentials

In this paper we consider quantum metastability in a class of moving potentials introduced by Berry and Klein. Potential in this class has its height and width scaled in a specific way so that it can be transformed into a stationary one. In deriving the non-decay probability of the system, we argue that the appropriate technique to use is the less known method of scattering states. This method is illustrated through two examples, namely, a moving delta-potential and a moving barrier potential. For expanding potentials, one finds that a small but finite non-decay probability persists at large times. Generalization to scaling potentials of arbitrary shape is briefly indicated.Comment: 10 pages, 1 figure

Sampling redesign of soil penetration resistance in spatial t-Student models

 Aim of study: To reduce the sample size in an agricultural area of 167.35 hectares, cultivated with soybean, to analyze the spatial dependence of soil penetration resistance (SPR) with outliers.Area of study: Cascavel, BrazilMaterial and methods: The reduction of sample size was made by the univariate effective sample size ( ) methodology, assuming that the t-Student model represents the probability distribution of SPR.Main results: The radius and the intensity of spatial dependence have an inverse relationship with the estimated value of the . For the depths of SPR with spatial dependence, the highest estimated value of the  reduced the sample size by 40%. From the new sample size, the sampling redesign was performed. The accuracy indexes showed differences between the thematic maps with the original and reduced sampling designs. However, the lowest values of the standard error in the parameters of the spatial dependence structure evidenced that the new sampling design was appropriate. Besides, models of semivariance function were efficiently estimated, which allowed identifying the existence of spatial dependence in all depth of SPR.Research highlights: The sample size was reduced by 40%, allowing for lesser financial investments with data collection and laboratory analysis of soil samples in the next mappings in the agricultural area. The spatial t-Student model was able to reduce the influence of outliers in the spatial dependence structure