2,574 research outputs found

    Non BPS noncommutative vortices

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    We construct exact vortex solutions to the equations of motion of the Abelian Higgs model defined in non commutative space, analyzing in detail the properties of these solutions beyond the BPS point. We show that our solutions behave as smooth deformations of vortices in ordinary space time except for parity symmetry breaking effects induced by the non commutative parameter θ\theta.Comment: 17 pages, 5 figure

    Thirring Model with Non-conserved Chiral Charge

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    We study the Abelian Thirring Model when the fermionic fields have non-conserved chiral charge: ΔQ5=N\Delta {\cal Q}_5 =N. One of the main features we find for this model is the dependence of the Virasoro central charge on both the Thirring coupling constant and NN. We show how to evaluate correlation functions and in particular we compute the conformal dimensions for fermions and fermionic bilinears, which depend on the fermionic chiral charge. Finally we build primary fields with arbitrary conformal weight.Comment: pages 1

    Importance of nuclear effects in the measurement of neutrino oscillation parameters

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    We investigate how models for neutrino-nucleus cross sections based on different assumptions for the nuclear dynamics affect the forecasted sensitivities to neutrino oscillation parameters at future neutrino facilities. We limit ourselves to the quasi-elastic regime, where the neutrino cross sections can be evaluated with less uncertainties, and discuss the sensitivity reach to theta_{13} and the CP violation phase at a prototype low-gamma beta-beam, mostly sensitive to the quasi-elastic regime.Comment: Error in cross section implementation corrected and sensitivities reevaluated accordingly. Relative performance of diffrent models and conclusions unchanged. Version to be published in PL

    Innovative coordination of agribusiness chains and networks

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    To facilitate scientifically grounded innovative forms of strategic network coordination, this paper integrates two major bodies of literature on competitive advantage. The two bodies of literature are the industry-oriented outside-in approach, and the competence-oriented inside-out approach, here homogenized along the dimensions of degrees of firm embeddedness, respectively, the broadness of shared resource bases. The elements detailed are interfirm relationships, resource bases, network governance instruments, coordination mechanisms, the impact of events on network structures, and the active mobilisation of actors and resource. Thereby, the paper is able to detail 5 generic types of business networks. Next, it relates 21 network governance instruments to type of partnerships (binding vs loosening), forms of interaction (cooperative vs opportunistic). The realized reduction of network complexity enhances conceptual transparency and increases the instrumental usage of this research for effective network coordination by businesses. An integrated case illustrates the usefulness of the various concepts and the coherency of the different elements

    The divergent transitions towards sustainable biofuel networks/chains

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    In this exploratory paper we investigate how Capabilities, Transaction Costs and Vertical Scope co-evolve, by testing the Jacobides & Winter (2005) model on the Biofuels Industry in the area of the EU. The theoretical framework is based on the Industrial Architecture theory but also on Transaction Costs Economics, Resource Based View and on the concept of the Dynamic Capabilities. Qualitative data on the institutional environment of the Biofuels Industry in the EU-15 was collected. Via interviews, qualitative data (case studies) was collected through interviews on the elements of productive capabilities, the vertical division of labour, knowledge and technology and attributes of the transactions. These conclusions include the verification of mechanisms 1 & 2 of the Jacobides & Winter (2005) model, in particular that the resources and capabilities determine the degree of vertical specialisation, with transactions costs as moderating factor. The conclusions of this project bring the need for further investigation on measuring the concepts of Capabilities and Transaction Costs together but also, on how to prescribe and measure the process of Capabilities development and the capabilities redistribution

    The macro-environment for liquid biofuels in the German science, mass, media and government

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    The purpose of this study is to investigate under which dimensions the macro-environment for liquid biofuels has been structured during time, respectively by science, mass media, and government in Germany, and how these three social expressions related to each other. Research was carried out on German official government documents, mass media news, and scientific papers on the topic 'liquid biofuels'. Text Mining was used to extract knowledge from their content. The results indicate that in configurating the macro-environment for liquid biofuels there is some degree of proximity between media and government, less between media and science, and the least between government and science

    The Choice of Marketing Cooperative in a Transition Agriculture

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    The agriculture in transition countries can be described by considerable uncertainties. In these countries public institutions are ineffective in ensuring contract enforcement. The absence of enforceable contract to set up any kind of vertical co-ordination has become difficult. In addition, this creates severe barriers for price discovery involving high transaction costs to co-ordinate market exchanges. Although there is a wealth of literature on marketing cooperative, but research on their role in transition agriculture is scarce. This paper tries to contribute to this gap. In this paper we have analysed the potential benefits and costs of the marketing cooperatives in Hungary employing transaction cost economics framework. The results presented add to a small literature on the marketing cooperatives in transition agriculture. We found that the quantity, the existence of contract, flexibility and trust are the most important factor for farmers to selling their product via cooperative. The cluster analysis provides some additional insights regarding farmers' choices. Namely, direct benefits including price, input finance extension services and speed of payments from cooperative membership have also important role. The most striking result is that the diversification and reputation has positive influences on the share of cooperative. Furthermore, large farmers have less willingness to sell their product to the cooperative. Surprisingly, asset specificity has rather negative effects on the share of cooperative.Agribusiness,
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