Is the transition redshift a new cosmological number?

Observations from Supernovae Type Ia (SNe Ia) provided strong evidence for an expanding accelerating Universe at intermediate redshifts. This means that the Universe underwent a transition from deceleration to acceleration phases at a transition redshift $z_t$ of the order unity whose value in principle depends on the cosmology as well as on the assumed gravitational theory. Since cosmological accelerating models endowed with a transition redshift are extremely degenerated, in principle, it is interesting to know whether the value of $z_t$ itself can be observationally used as a new cosmic discriminator. After a brief discussion of the potential dynamic role played by the transition redshift, it is argued that future observations combining SNe Ia, the line-of-sight (or "radial") baryon acoustic oscillations, the differential age of galaxies, as well as the redshift drift of the spectral lines may tightly constrain $z_t$, thereby helping to narrow the parameter space for the most realistic models describing the accelerating Universe.Comment: 12 pages, 5 figures. Some discussions about how to estimate the transition redshift have been added. New data by Planck and H(z) data have been mentioned. New references have been adde

New coupled quintessence cosmology

A component of dark energy has been recently proposed to explain the current acceleration of the Universe. Unless some unknown symmetry in Nature prevents or suppresses it, such a field may interact with the pressureless component of dark matter, giving rise to the so-called models of coupled quintessence. In this paper we propose a new cosmological scenario where radiation and baryons are conserved, while the dark energy component is decaying into cold dark matter (CDM). The dilution of CDM particles, attenuated with respect to the usual $a^{-3}$ scaling due to the interacting process, is characterized by a positive parameter $\epsilon$, whereas the dark energy satisfies the equation of state $p_x=\omega \rho_x$ ($\omega < 0$). We carry out a joint statistical analysis involving recent observations from type Ia supernovae, baryon acoustic oscillation peak, and Cosmic Microwave Background shift parameter to check the observational viability of the coupled quintessence scenario here proposed.Comment: 7 pages, 7 figures. Minor corrections to match published versio

Budgetary balances adjustments from governmental accounting to national accounts in EU countries: can deficits be prone to management?

European Union (EU) countries are required to achieve deficit targets and are thus incentivized to use tools to keep within budgetary limits. This paper argues that accounting discretion might be used to manage some adjustments made during the translation of data from Governmental Accounting (GA) into National Accounts (NA), to window‐dress the final deficit/surplus reported to EUROSTAT. The empirical research shows there are certain circumstances that might facilitate the use of GA–NA “adjustment discretion.” EU authorities must pay special attention to these conditions to ensure the reliability of reported deficits. The main findings of this paper could also assist in future efforts to improve the integrity of the adjustment process.info:eu-repo/semantics/acceptedVersio

Levantamento do consumo de água para processamento da cana-de-açúcar na região de abrangência do Pólo Centro-Sul, Piracicaba, SP.

Resumo: A região de Piracicaba é tradicional produtora de cana-de-açúcar e na safra 2012/13 apresentou 327 mil hectares de área plantada. Os benefícios ambientais gerados com a eliminação da queima da cana para fins de colheita, também repercutem na diminuição do consumo de água pelas usinas. Com a introdução do novo sistema de colheita não é mais necessário, via de regra, o uso da água para a lavagem da cana-de-açúcar. No levantamento realizado para o Protocolo Agroambiental, feito nas usinas signatárias e com atividade na região de abrangência do Pólo Centro ? Sul da APTA, foi possível constatar que as 14 usinas desta região consomem em média 1,97 mm de água por tonelada de cana-de-açúcar. Esse trabalho apresenta os dados de precipitação pluviométrica da estação climatológica da Unidade de Pesquisa e Desenvolvimento ? UPD (antiga estação experimental de Tietê) da Agência Paulista de Tecnologia dos Agronegócios ? APTA, no período de 2009 a 2014

A Method for Obtaining Cosmological Models Consistency Relations and Gaussian Processes Testing

In the present work, we apply consistency relation tests to several cosmological models, including the flat and non-flat $\Lambda$CDM models, as well as the flat XCDM model. The analysis uses a non-parametric Gaussian Processes method to reconstruct various cosmological quantities of interest, such as the Hubble parameter $H(z)$ and its derivatives from $H(z)$ data, as well as the comoving distance and its derivatives from SNe Ia data. We construct consistency relations from these quantities which should be valid only in the context of each model and test them with the current data. We were able to find a general method of constructing such consistency relations in the context of $H(z)$ reconstruction. In the case of comoving distance reconstruction, there were not a general method of constructing such relations and this work had to write an specific consistency relation for each model. From $H(z)$ data, we have analyzed consistency relations for all the three above mentioned models, while for SNe Ia data we have analyzed consistency relations only for flat and non-flat $\Lambda$CDM models. Concerning the flat $\Lambda$CDM model, some inconsistency was found, at more than $2\sigma$ c.l., with the $H(z)$ data in the interval $1.8\lesssim z\lesssim2.4$, while the other models were all consistent at this c.l. Concerning the SNe Ia data, the flat $\Lambda$CDM model was consistent in the $0<z<2.5$ interval, at $1\sigma$ c.l., while the nonflat $\Lambda$CDM model was consistent in the same interval, at 2$\sigma$ c.l.Comment: 17 pages and 7 figure

Mecanização no cultivo de cana-de-açúcar como componente de sustentabilidade: o caso de Piracicaba/SP e Quirinópolis/GO.

Resumo: A mecanização dos sistemas produtivos de cana-de-açúcar tem sido intensa nos últimos anos devido às pressões da sociedade que buscam produtos com melhor qualidade e ecologicamente corretos. Do lado do produtor, existe também a busca por menores custos de produção na colheita. A expansão da cana-de-açúcar tem ocorrido de forma mais intensa nos estados do centro-oeste do Brasil, estes, por sua vez, têm apresentado altas taxas de mecanização graças à baixa declividade dos terrenos e ao alto investimento tecnológico. Esse trabalho tem por objetivo avaliar duas regiões de produção de cana: a região tradicional para produção de cana, Piracicaba/SP, e uma região de expansão, Quirinópolis/GO. Desse modo, estudar o funcionamento e características dos sistemas de produção de cana-de-açúcar no estado de São Paulo e as mudanças necessárias para os novos ambientes de produção pode ser a chave para entender com maior clareza as inovações eminentes para o setor e com isso definir instrumentos para apoiá-los de modo mais efetivo