11,217 research outputs found

    Higher U(1)-gerbe connections in geometric prequantization

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    We promote geometric prequantization to higher geometry (higher stacks), where a prequantization is given by a higher principal connection (a higher gerbe with connection). We show fairly generally how there is canonically a tower of higher gauge groupoids and Courant groupoids assigned to a higher prequantization, and establish the corresponding Atiyah sequence as an integrated Kostant-Souriau infinity-group extension of higher Hamiltonian symplectomorphisms by higher quantomorphisms. We also exhibit the infinity-group cocycle which classifies this extension and discuss how its restrictions along Hamiltonian infinity-actions yield higher Heisenberg cocycles. In the special case of higher differential geometry over smooth manifolds we find the L-infinity-algebra extension of Hamiltonian vector fields -- which is the higher Poisson bracket of local observables -- and show that it is equivalent to the construction proposed by the second author in n-plectic geometry. Finally we indicate a list of examples of applications of higher prequantization in the extended geometric quantization of local quantum field theories and specifically in string geometry.Comment: Title changed. Exposition revised. 55 page

    Integrated Support for Handoff Management and Context-Awareness in Heterogeneous Wireless Networks

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    The overwhelming success of mobile devices and wireless communications is stressing the need for the development of mobility-aware services. Device mobility requires services adapting their behavior to sudden context changes and being aware of handoffs, which introduce unpredictable delays and intermittent discontinuities. Heterogeneity of wireless technologies (Wi-Fi, Bluetooth, 3G) complicates the situation, since a different treatment of context-awareness and handoffs is required for each solution. This paper presents a middleware architecture designed to ease mobility-aware service development. The architecture hides technology-specific mechanisms and offers a set of facilities for context awareness and handoff management. The architecture prototype works with Bluetooth and Wi-Fi, which today represent two of the most widespread wireless technologies. In addition, the paper discusses motivations and design details in the challenging context of mobile multimedia streaming applications

    Resistance to frost and tuber soft rot in near-pentaploid Solanum tuberosum - S. commersonii hybrids

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    The objectives of the present study were to evaluate the tolerance to low temperatures and tuber soft rot in sexual near-pentaploid hybrids between incongruent 2x (1EBN) Solanum commersonii (CMM) and 4x (4EBN) S. tuberosum (TBR). For freezing resistance, killing temperatures both under non-acclimated and un- der acclimated conditions were determined using the ion leakage procedure. Values for the hybrids were dis- tributed between the wild and cultivated parental values. Some hybrids displayed an acclimation capacity close to 2.5°C, typical of hardy species. Artificial inoculation of tubers with Pectobacterium carotovorum ssp. carotovorum (formerly Erwinia carotovora ssp. carotovora) provided evidence of variability in disease response. Highly resistant hybrids were identified. After conventional phenotypic selection, wild genome content was estimated based on the presence of CMM-specific AFLP fragments. Seven primer combinations were used (Eco-AGG/Mse-CAA; Eco-ACC/Mse-CAT; Eco-ACT/Mse-CAC; Eco-ACT/Mse-CAG; Eco- ACT/Mse-CAA; Eco-ACT/Mse-CAT; Eco-AGG/Mse-CAG). The percentages of CMM-specific AFLPs ranged from 4.3% to 56.7%, with an average value of 28.1%. AFLP analysis was employed for the selection of the hybrids to be used for further breeding objectives

    Early music influences in Paul Hindemith\u27s Compositions for the Viola

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    It is widely recognized that several of Paul Hindemith’s compositions display a significant use of early music forms and techniques. Yet, the scholarly literature in English focusing specifically on the influence of early music on Hindemith’s works for the viola is limited. Thus, through a discussion of selected works for solo viola and viola and orchestra, with a concentration on the two finales of the solo viola sonatas op. 11, no. 5, and op. 31, no. 4, the viola concerto Der Schwanendreher, and the Trauermusik for viola and strings, this document investigates the impact of early music on Hindemith’s compositional output for the viola. The findings of this research reveal that the study and practice of early music had a crucial influence on Hindemith’s compositional output, specifically illustrated through the use of early music techniques including fugues, ostinatos, chorale settings, canons, theme and variations, cantus firmus-like melodies, and the borrowing of old folksongs and chorales. Scholars should not exclude the possibility that early music influence extends beyond the examples presented in this thesis

    Asymptotic Expansion for the Wave Function in a one-dimensional Model of Inelastic Interaction

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    We consider a two-body quantum system in dimension one composed by a test particle interacting with an harmonic oscillator placed at the position a>0a>0. At time zero the test particle is concentrated around the position R0R_0 with average velocity ±v0\pm v_0 while the oscillator is in its ground state. In a suitable scaling limit, corresponding for the test particle to a semi-classical regime with small energy exchange with the oscillator, we give a complete asymptotic expansion of the wave function of the system in both cases R0<aR_0 <a and R0>aR_0 >a.Comment: 23 page
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