Recovery of fluctuation spectrum evolution from tomographic shear spectra

Forthcoming large angle surveys are planned to obtain high precision tomographic shear data. In principle, they will allow us to recover the spectra of matter density fluctuation, at various redshift, through the inversion of the expressions yielding shear from fluctuation spectra. This was discussed in previous work, where SVD techniques for matrix inversion were also shown to be the optimal tool to this aim. Here we show the significant improvements obtainable by using a 7 bin tomography, as allowed by future Euclid data, as well as the question of error propagation from shear to fluctuation spectra. We find that the technique is a promising tool, namely for the analysis of baryon physics throug high-l shear spectra and to test the consistency between expansion rate and fluctuation growth.Comment: 22 pages, 10 figure

"Organic District": identification methodology and agricultural policy objectives

Italy, unlike other countries, has included the territorial dimension in the recent interventions and regulations of organic agriculture, introducing explicitly the concept of “organic district”. It is defined as a local productive system with a high agricultural vocation where organic production and processing practices are predominant. The main object of this new subject is to promote the diffusion of organic agriculture focusing on the productive and environmental territorial characteristic. In this poster, after a general definition of the organic districts, as they are introduced in the Italian regulations, a method for their identification in a region is proposed. In the final part, some considerations about the role of the organic district within the general framework of agro-environmental policies are developed.organic district, agro-environmental policies, organic agriculture, Agricultural and Food Policy, Environmental Economics and Policy,

Sample variance in N--body simulations and impact on tomographic shear predictions

We study the effects of sample variance in N--body simulations, as a function of the size of the simulation box, namely in connection with predictions on tomographic shear spectra. We make use of a set of 8 $\Lambda$CDM simulations in boxes of 128, 256, 512 $h^{-1}$Mpc aside, for a total of 24, differing just by the initial seeds. Among the simulations with 128 and 512 $h^{-1}$Mpc aside, we suitably select those closest and farthest from {\it average}. Numerical and linear spectra $P(k,z)$ are suitably connected at low $k$ so to evaluate the effects of sample variance on shear spectra $C_{ij}(\ell)$ for 5 or 10 tomographic bands. We find that shear spectra obtained by using 128 $h^{-1}$Mpc simulations can vary up to $\sim 25\, \%$, just because of the seed. Sample variance lowers to $\sim 3.3\, \%$, when using 512 $h^{-1}$Mpc. These very percentages could however slightly vary, if other sets of the same number of realizations were considered. Accordingly, in order to match the $\sim 1\, \%$ precision expected for data, if still using 8 boxes, we require a size $\sim 1300$ --$1700 \, h^{-1}$ Mpc for them.Comment: accepted by Ap

Constraints on Dark Energy state equation with varying pivoting redshift

We assume the DE state equations w(a) = w_0+w_a(a_p-a), and study the dependence of the constraints on w_0 and w_a coefficients on the pivoting redshift 1+z_p=1/a_p. Coefficients are fitted to data including WMAP7, SNIa (Union 2.1), BAO's (including WiggleZ and SDSS results) and H_0 constraints. The fitting algorithm is CosmoMC. We find specific differences between the cases when neutrino mass is allowed or disregarded. More in detail: i) The z_p value yielding uncorrelated constraints on w_0 and w_a is different in the two cases, holding ~0.25 and ~0.35, respectively. (ii) If we consider the intervals allowed to w_0, we find that they shift when z_p increases, in opposite directions for vanishing or allowed neutrino mass. This leads to no overlap between 1sigma intervals already at z_p >~0.4. (iii) The known effect that a more negative state parameter is required to allow for neutrino mass displays its effects on w_a, rather than on w_0. (iv) The w_0-w_a constraints found by using any pivot z_p can be translated into constraints holding at a specific z_p value (0 or the z_p where errors are uncorrelated). When we do so, error ellipses exhibit a satisfactory overlap.Comment: 13 pages, 7 figures, 2 table

Back to the Future? Understanding Change in Food Habits of Farmers' Market Customers

farmers' markets, food habits, Italy, Agribusiness, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Health Economics and Policy,

Ivan Jordović, Taming Politics. Plato and the Democratic Roots of Tyrannical Man

De nombreuses publications analysent par différents biais l’idéologie de la démocratie et la déconstruisent, tout en relevant les liens qui existent entre la pensée démocratique et la pensée aristocratique (voire oligarchique ou tyrannique). L’ouvrage de Luciano Canfora de 2004 (La democrazia. Storia di un’ideologia), qui retrace l’histoire de l’idéologie démocratique et a soulevé de nombreuses polémiques, a notamment montré qu'il s'agit là d'un terrain glissant. Dans son introduction, Ivan J..

A “Constituição dos Atenienses” de Pseudo-Xenofonte

The Constitution of the Athenians is a short work about the politeia of Athens and the conditions by which Athenian democracy can last as constitutional regime which manages the life of the polis. This work represents both a philological and a historiographical problem, because, even if it was transmitted in the corpus of Xenophon’s work, it is considered to have been written by another author, known as Speudo-Xenophon or “Old Oligarch”. It is an oligarchic pamphlet which presents Athens as an upside down world, where the worst people rule and the best ones are as reduced to slavery by the ignorant multitude.A Constituição dos Atenienses é uma pequena obra acerca da politeia de Atenas e das condições que permitem que a democracia permaneça em Atenas como forma de gerenciar a vida da polis. Esta obra representa um problema filológico e historiográfico, porque, embora esteja no corpus das obras de Xenofonte, ela é considerada obra de outro autor, conhecido como Pseudo-Xenofonte ou “Velho Oligarca”. Trata-se de um pamphlet de orientação oligárquica que apresenta Atenas como um mundo ao contrário, em que os piores comandam e os melhores são como escravizados pela multidão ignorante