N=8 BPS black holes preserving 1/8 supersymmetry

In the context of N=8 supergravity we consider BPS black-holes that preserve 1/8 supersymmetry. It was shown in a previous paper that, modulo U-duality transformations of E_{7(7)} the most general solution of this type can be reduced to a black-hole of the STU model. In this paper we analize this solution in detail, considering in particular its embedding in one of the possible Special K\"ahler manifold compatible with the consistent truncations to N=2 supergravity, this manifold being the moduli space of the T^6/Z^3 orbifold, that is: SU(3,3)/SU(3)*U(3). This construction requires a crucial use of the Solvable Lie Algebra formalism. Once the group-theoretical analisys is done, starting from a static, spherically symmetric ans\"atz, we find an exact solution for all the scalars (both dilaton and axion-like) and for gauge fields, together with their already known charge-dependent fixed values, which yield a U-duality invariant entropy. We give also a complete translation dictionary between the Solvable Lie Algebra and the Special K\"ahler formalisms in order to let comparison with other papers on similar issues being more immediate. Although the explicit solution is given in a simplified case where the equations turn out to be more manageable, it encodes all the features of the more general one, namely it has non-vanishing entropy and the scalar fields have a non-trivial radial dependence.Comment: 29+1 pages, 1 Latex file; a misprint in the entropy formula, eq.(5.14), correcte

More Anomalies from Fractional Branes

In this note we show how the anomalies of both pure and matter coupled N=1,2 supersymmetric gauge theories describing the low energy dynamics of fractional branes on orbifolds can be derived from supergravity.Comment: 11 pages, latex; v2: minor typos fixe

N=2 four-dimensional gauge theories from fractional branes

This is a pedagogical and extended version of the results published in Refs. [1,2] and presented by the authors in various talks during the last year. We discuss the type II D-branes (both regular and fractional) of the orbifold R^{1,5}*R^4/Z_2, we determine their corresponding supergravity solution and show how this can be used to study the properties of N=2 super Yang-Mills. Supergravity is able to reproduce the perturbative moduli space of the gauge theory, while it does not encode the non-perturbative corrections. The short distance region of space-time, which corresponds to the infrared region of the gauge theory, is excised by an enhancon mechanism, and more states should be included in the low energy effective action in order to enter inside the enhancon and recover the instanton corrections. (To be published on a Memorial Volume commemorating Michael Marinov)Comment: 44 pages, AMS-LaTeX, no figure

Overview on Rural Poverty in Developed Countries

Despite the long tradition of intervention, rural poverty is still an important issue to face in the economic and social growth of developed countries. Often hidden for many reason recalled in the paper, rural poverty is transmitted by the cumulative negative effects of vicious circle of labour market, demography, education and remoteness. Agricultural and rural policy with social policy has reached important result for reducing rural poverty in developed countries, especially promoting diversification of rural area and sustainability approach to the production. The paper underlines the role of coordination between top-down and place-based policies, as well as the indicators for adapting policies and having successful intervention, shortly discussing some examples of good practices

Fractional Branes and N=1 Gauge Theories

We discuss fractional D3-branes on the orbifold C^3/Z_2*Z_2. We study the open and the closed string spectrum on this orbifold. The corresponding N=1 theory on the brane has, generically, a U(N_1)*U(N_2)*U(N_3)*U(N_4) gauge group with matter in the bifundamental. In particular, when only one type of brane is present, one obtains pure N=1 Yang-Mills. We study the coupling of the branes to the bulk fields and present the corresponding supergravity solution, valid at large distances. By using a probe analysis, we are able to obtain the Wilsonian beta-function for those gauge theories that possess some chiral multiplet. Although, due to the lack of moduli, the probe technique is not directly applicable to the case of pure N=1 Yang-Mills, we point out that the same formula gives the correct result also for this case.Comment: 21 pages, AMS-LaTeX, v2: references added and typos correcte

Closed string exchanges on C2/Z2C^2/Z_2 in a background B-field

In an earlier work it was shown that the IR singularities arising in the nonplanar one loop two point function of a noncommutative ${\cal N}=2$ gauge theory can be reproduced exactly from the massless closed string exchanges. The noncommutative gauge theory is realised on a fractional $D_3$ brane localised at the fixed point of the $C^2/Z_2$ orbifold. In this paper we identify the contributions from each of the closed string modes. The sum of these adds upto the nonplanar two-point function.Comment: 27 page

Supersymmetry breaking at the end of a cascade of Seiberg dualities

We study the IR dynamics of the cascading non-conformal quiver theory on N regular and M fractional D3 branes at the tip of the complex cone over the first del Pezzo surface. The horizon of this cone is the irregular Sasaki-Einstein manifold Y^{2,1}. Our analysis shows that at the end of the cascade supersymmetry is dynamically broken.Comment: 12 pages, 2 figures, minor changes, typos correcte

The Trispectrum in the Effective Field Theory of Large Scale Structure

We compute the connected four point correlation function (the trispectrum in Fourier space) of cosmological density perturbations at one-loop order in Standard Perturbation Theory (SPT) and the Effective Field Theory of Large Scale Structure (EFT of LSS). This paper is a companion to our earlier work on the non-Gaussian covariance of the matter power spectrum, which corresponds to a particular wavenumber configuration of the trispectrum. In the present calculation, we highlight and clarify some of the subtle aspects of the EFT framework that arise at third order in perturbation theory for general wavenumber configurations of the trispectrum. We consistently incorporate vorticity and non-locality in time into the EFT counterterms and lay out a complete basis of building blocks for the stress tensor. We show predictions for the one-loop SPT trispectrum and the EFT contributions, focusing on configurations which have particular relevance for using LSS to constrain primordial non-Gaussianity.Comment: 25+3 pages, 7 figure

Le specificità del sistema agro-alimentare nella ricostruzione post-sisma

Anche il cosiddetto ‘cratere agricolo’ ha pagato un prezzo molto elevato a seguito degli eventi sismici del maggio 2012 in Emilia. Tutte le principali produzioni agro-industriali del territorio hanno subito gravi danni: si pensi ai caseifici e magazzini di stagionatura per la produzione di Parmigiano Reggiano, alle cantine e acetaie, alle celle frigorifere per la conservazione dei prodotti ortofrutticoli. Il presente lavoro analizza i principali elementi di specificità che, rispetto ad una forte vulnerabilità settoriale, hanno caratterizzato la ricostruzione del patrimonio agricolo e agro-industriale del cratere. Grande attenzione è data, ad esempio, alla risposta istituzionale per la ricostruzione. Come il settore industriale, infatti, anche il settore agro-alimentare ha beneficiato dei contributi per la ricostruzione attraverso la piattaforma SFINGE. Tuttavia, esso ha altresì beneficiato delle risorse stanziate attraverso il FEASR (Fondo Europeo Agricolo per lo Sviluppo Rurale): l’attivazione di specifiche misure ha permesso di sostenere l’intero territorio del cratere del sisma. Un ulteriore elemento di specificità evidenziato è rappresentato dal tema dell’associazionismo (attivazione di accordi di filiera, interventi di solidarietà e mutualistici) e dal ruolo ricoperto dai Consorzi di Tutela delle produzioni tipiche. Il lavoro dunque evidenzia come, nonostante le criticità riscontrate, il settore agro-alimentare abbia saputo cogliere alcune opportunità dall’evento sismico, soprattutto in termini di capacità innovativa. Abstract: The 2012 earthquake in Emilia-Romagna (Italy) affected a broad area that is characterized by the presence of important industrial and agricultural districts. Indeed, dairies producing Parmigiano Reggiano cheese, firms producing balsamic vinegar of Modena (acetaie) as well as wineries have been particularly damaged. This work focuses on those specific features of agricultural activities that have affected the reconstruction process as well. According to those specificities, the paper points out regulatory interventions that were approved, aiming to guarantee appropriate financial support to the agri-industrial activities damaged by the earthquake. Specific focus is devoted to the role played by the European Agricultural Fund for Rural Development (EAFRD). Eventually, the role played by the cooperative system is stressed as well. According to this analysis, agri-food sector has been proven quite innovative, despite many limits affecting it