7,224 research outputs found

    On Schwarzschild's Topology in Brane-Worlds

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    The topological structure of Schwarzschild's space-time and its maximal analytic extension are investigated in context of brane-worlds. Using the embedding coordinates, these geometries are seen as different states of the evolution of a single brane-world. Comparing the topologies and the embeddings it is shown that this evolution must be followed by a signature change in the bulk.Comment: 6 page

    Particle Creation by a Moving Boundary with Robin Boundary Condition

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    We consider a massless scalar field in 1+1 dimensions satisfying a Robin boundary condition (BC) at a non-relativistic moving boundary. We derive a Bogoliubov transformation between input and output bosonic field operators, which allows us to calculate the spectral distribution of created particles. The cases of Dirichlet and Neumann BC may be obtained from our result as limiting cases. These two limits yield the same spectrum, which turns out to be an upper bound for the spectra derived for Robin BC. We show that the particle emission effect can be considerably reduced (with respect to the Dirichlet/Neumann case) by selecting a particular value for the oscillation frequency of the boundary position

    Deliberation across Deep Divisions. Transformative Moments

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    In group discussions of any kind there tends to be an up and down in the level of deliberation. To capture this dynamic we coined the concept of Deliberative Transformative Moments (DTM). In deeply divided societies deliberation is particularly important in order to arrive at peace and stability, but deliberation is also very difficult to be attained. Therefore, we wanted to learn about the conditions that in group discussions across the deep divisions of such societies help deliberation. We organized such group discussions between ex-guerrillas and ex-paramilitaries in Colombia, Serbs and Bosnjaks in Srebrenica, and poor residents and local police officers in the favelas (slums) of Brazil. We could identify factors that help to transform discussions from low to high deliberation and risk transformations in the opposite direction. We could also identify factors that help to keep a discussion at a high level of deliberation, and, in a next step, we could determine to what extent long sequences of deliberation had a positive impact on the outcomes of the discussions. Finally, we show how our research results can have a long term effect if it is used in schools of such deeply divided societies

    Recognition and the media

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    Recognition and the media recopila los aportes al campo de la comunicación y al estudio de los medios que viene desarrollando Rousiley Maia sobre la base de la teoría crítica de Axel Honneth, desde 1998 tras su formación posgradual en Política en la Universidad de Nottingham (UK) y como directora del grupo de investigación Pesquisa em Mídia e Esfera Pública (EME), de la Universidade Federal de Minas Gerais (UFMG) en Brasil.Recognition and the media recopila los aportes al campo de la comunicación y al estudio de los medios que viene desarrollando Rousiley Maia sobre la base de la teoría crítica de Axel Honneth, desde 1998 tras su formación posgradual en Política en la Universidad de Nottingham (UK) y como directora del grupo de investigación Pesquisa em Mídia e Esfera Pública (EME), de la Universidade Federal de Minas Gerais (UFMG) en Brasil

    Deliberation across Deep Divisions. Transformative Moments

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    From the local level to international politics, deliberation helps to increase mutual understanding and trust, in order to arrive at political decisions of high epistemic value and legitimacy. This book gives deliberation a dynamic dimension, analysing how levels of deliberation rise and fall in group discussions, and introducing the concept of 'deliberative transformative moments' and how they can be applied to deeply divided societies, where deliberation is most needed but also most difficult to work. Discussions between ex-guerrillas and ex-paramilitaries in Colombia, Serbs and Bosnjaks in Bosnia-Herzegovina, and police officers and locals in Brazilian favelas are used as case studies, with participants addressing how peace can be attained in their countries. Allowing access to the records and transcripts of the discussions opens an opportunity for practitioners of conflict resolution to apply this research to their work in trouble spots of the world, creating a link between the theory and practice of deliberation
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