1,739 research outputs found

    Cyclic homogeneous Riemannian manifolds

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    In spin geometry, traceless cyclic homogeneous Riemannian manifolds equipped with a homogeneous spin structure can be viewed as the simplest manifolds after Riemannian symmetric spin spaces. In this paper, we give some characterizations and properties of cyclic and traceless cyclic homogeneous Riemannian manifolds and we obtain the classification of simply-connected cyclic homogeneous Riemannian manifolds of dimension less than or equal to four. We also present a wide list of examples of non-compact irreducible Riemannian 33-symmetric spaces admitting cyclic metrics and give the expression of these metrics

    Homogeneous spin Riemannian manifolds with the simplest Dirac operator

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    We show the existence of nonsymmetric homogeneous spin Riemannian manifolds whose Dirac operator is like that on a Riemannian symmetric spin space. Such manifolds are exactly the homogeneous spin Riemannian manifolds (M,g)(M,g) which are traceless cyclic with respect to some quotient expression M=G/KM=G/K and reductive decomposition g=km\mathfrak{g} = \mathfrak{k} \oplus \mathfrak{m}. Using transversally symmetric fibrations of noncompact type, we give a list of them

    Improved thermal isolation of silicon suspended platforms for an all-silicon thermoelectric microgenerator based on large scale integration of Si nanowires as thermoelectric material

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    Special suspended micro-platforms have been designed as a part of silicon compatible planar thermoelectric microgenerators. Bottom-up grown silicon nanowires are going to bridge in the future such platforms to the surrounding silicon bulk rim. They will act as thermoelectric material thus configuring an all-silicon thermoelectric device. In the new platform design other additional bridging elements (usually auxiliary support silicon beams) are substituted by low conductance thin film dielectric membranes in order to maximize the temperature difference developed between both areas. These membranes follow a sieve-like design that allows fabricating them with a short additional wet anisotropic etch step. © Published under licence by IOP Publishing Ltd.Peer ReviewedPostprint (published version

    Alterated Identities in Brazil: From the Samba Culture to the Sertanejo Culture

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    Cultural references regarding Brazilianness have generally been associated with samba, carnival, colors, and an aesthetic compendium typical of a pre-modernity recreated in cities like Rio de Janeiro or Salvador. A foreign observer would like to see in these lands references that would transport him to Antônio Carlos Jobim’s “The Girl from Ipanema” song or to identity traits that would indicate a ‘tropical Brazil’ related to people dancing in the rhythm of samba and bossa nova, and Copacabana beach. However, many socio-cultural changes progressively impacted the consumption of musical and aesthetic styles among Brazilians. Changes concerning musical styles’ preferences led to significant cultural changes that would modify the notion of Brazilianness imaginary in the first decades of the 21st century. The present paper addresses this eventual cultural and aesthetic references change, showing with decisive force what has been called ‘sertanejo culture’ in Brazil. Keywords: Brazilian culture; Cultural identity; Samba culture; Sertanejo culture; Musical styles. DOI: 10.7176/RHSS/12-18-04 Publication date:September 30th 202

    Business cycle patterns in European regions

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    The aim of this paper is threefold. First, we analyze the comovements of business cycles in European regions. Second, we date these business cycles and identify clusters of regions with similar business cycle behavior, using Finite Mixture Markov models. Third, we develop a new index to measure within-country homogeneity. We find that comovement among regions is, on average, quite low, although it increased during the convergence process prior to the euro cash and after the onset of the Great Recession. We identify five different groups of European regions. We also find heterogeneity in the size of border effects

    HOMOGENEOUS RIEMANNIAN STRUCTURES ON BERGER 3-SPHERES

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    High-spin structure in K-40

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    High-spin states of K-40 have been populated in the fusion-evaporation reaction C-12(Si-30,np)K-40 and studied by means of gamma-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10(-) have been discovered. These states are discussed in terms of J = 3 and T = 0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum. ©2012 American Physical SocietyWe would like to thank the Swedish National Infrastructure for Computing (SNIC) and the Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) for the computer resources used in parts of the analysis.This work was financed by EURONS AGATA (Contract no. 506065-R113), the Swedish Research Council under contracts 621-2008-4163, 621-2011-4522, 822-2005-3332 and 821-2010-6024, the Japan Society for the Promotion of Science (JSPS) Kakenhi Grant No. 23·01752, Ankara University (BAP Project number 05B4240002), the Polish Ministry of Science and Higher Education under grants number DPN/N190/AGATA/2009 and N N202 073935, the German BMBF under Grants 06K-167, 06KY205I and 06KY9136I, the Knut and Alice Wallenberg Foundation contract number 2005.0184 and STFC (UK). A. Gadea and E. Farnea acknowledge the support of MICINN, Spain, and INFN, Italy through the AIC-D-2011-0746 bilateral action. A. Gadea’s activity has been partially supported by the Generalitat Valenciana, Spain, under grant PROMETEO/2010/101. A. Gadea, A. Jungclaus, A. Poves and B. Quintana acknowledge support from the MICINN, Spain, under grant FPA2011-29854. A. Pove is partially supported by the Comunidad de Madrid (Spain) (HEPHACOS S2009-ESP-1473). G. Jaworski acknowledges the support of the Center for Advanced Studies of Warsaw University of Technology. B. Cederwall acknowledge the support of the Göran Gustafsson FoundationPeer Reviewe
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