19,462 research outputs found
Hidden Conformal Symmetry in Randall-Sundrum 2 Model: Universal Fermion Localization by Torsion
In this manuscript we describe a hidden conformal symmetry of the second
Randall-Sundrum model (RS2). We show how this can be used to localize fermions
of both chiralities. The conformal symmetry leaves few free dimensionless
constants and constrains the allowed interactions. In this formulation the
warping of the extra dimension emerges from a partial breaking of the conformal
symmetry in five dimensions. The solution of the system can be described in two
alternative gauges: by the metric or by the conformon. By considering this as a
fundamental symmetry we construct a conformally invariant action for a vector
field which provides a massless photon localized over a Minkowski brane. This
is obtained by a conformal non-minimal coupling that breaks the gauge symmetry
in five dimensions. We further consider a generalization of the model by
including conformally invariant torsion. By coupling torsion non-minimally to
fermions we obtain a localized zero mode of both chiralities completing the
consistence of the model. The inclusion of torsion introduces a fermion quartic
interaction that can be used to probe the existence of large extra dimensions
and the validity of the model. This seems to point to the fact that conformal
symmetry may be more fundamental than gauge symmetry and that this is the
missing ingredient for the full consistence of RS scenarios.Comment: Published versio
Revisiting Bank Pricing Policies in Brazil: evidence from loan and deposit markets
This paper addresses the determinants of interest rates in the Brazilian banking market. The results suggest that banks fully adjust their loan interest rates to a change in the monetary policy rate, but we also observe a rigid short-term response for some loan product categories. The study confirms that pricing policies can vary substantially depending on the market. For example, microeconomic factors did not seem to be a major determinant of retail loan rates, but they were found to be important determinants of corporate loan or time deposit rates. As two additional results, market concentration was found to have a robust significant positive effect on loan rates and interest spreads, as well as the international risk perception of Brazil, as proxied by the EMBI Brazil.
Open access repository for the brazilian literature on agroecology.
The Brazilian technical and scientific literature on Agroecology is plentiful, is scattered and of difficult access and the hypothesis is that the knowledge of the area was produced but is composed by a knowledge to be organized. These features are barriers and constrains for farmers to use agricultural information as well as for providers of extension services to meet information needs of farmers. In this direction there is a consensus among researchers who study the information that the adequate alternative and adopted in the entire world are the open access digital repositories. Besides taking into account all essential actions to manage technical and scientific information, the open access digital repositories contribute to better communication process of Science. This occurs because such tools create necessary conditions to researchers to have timely, quickly, easy and perpetual access to the information they need to develop their activities. Also help to disseminate the results and provide increase on citation, researcher and institution visibility. A digital repository can be institutional or by topic where the institutional manages and fosters the scientific production of the institution as a whole. Repositories by topic make evident the stage of development of a scientific community. The objective is to describe how the collection of journal and magazines articles, conference papers, documents published by NGOs, government papers, dissertations and thesis, documents on the Internet, agricultural research produced by institutes and universities, etc. will be redeem to create and manage an open access digital repository of the Brazilian bibliographic production on Agroecology host by the Organic Eprints
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