5,705 research outputs found

    Water-based Liquid Scintillator Detector as a New Technology Testbed for Neutrino Studies in Turkey

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    This study investigates the deployment of a medium-scale neutrino detector near Turkey's first nuclear power plant, the Akkuyu Nuclear Power Plant. The aim of this detector is to become a modular testbed for new technologies in the fields of new detection media and innovative photosensors. Such technologies include Water-based Liquid Scintillator (WbLS), Large Area Picosecond Photo-Detectors (LAPPDs), dichroic Winston cones, and large area silicon photomultiplier modules. The detector could be used for instantaneous monitoring of the Akkuyu Nuclear Power Plant via its antineutrino flux. In addition to its physics and technological goals, it would be an invaluable opportunity for the nuclear and particle physics community in Turkey to play a role in the development of next generation of particle detectors in the field of neutrino physics.Comment: V2, updated version with additional reference

    hp-adaptive discontinuous Galerkin solver for elliptic equations in numerical relativity

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    A considerable amount of attention has been given to discontinuous Galerkin methods for hyperbolic problems in numerical relativity, showing potential advantages of the methods in dealing with hydrodynamical shocks and other discontinuities. This paper investigates discontinuous Galerkin methods for the solution of elliptic problems in numerical relativity. We present a novel hp-adaptive numerical scheme for curvilinear and non-conforming meshes. It uses a multigrid preconditioner with a Chebyshev or Schwarz smoother to create a very scalable discontinuous Galerkin code on generic domains. The code employs compactification to move the outer boundary near spatial infinity. We explore the properties of the code on some test problems, including one mimicking Neutron stars with phase transitions. We also apply it to construct initial data for two or three black holes

    Symmetry breaking in general relativity

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    Bifurcation theory is used to analyze the space of solutions of Einstein's equations near a spacetime with symmetries. The methods developed here allow one to describe precisely how the symmetry is broken as one branches from a highly symmetric spacetime to nearby spacetimes with fewer symmetries, and finally to a generic solution with no symmetries. This phenomenon of symmetry breaking is associated with the fact that near symmetric solutions the space of solutions of Einstein's equations does not form a smooth manifold but rather has a conical structure. The geometric picture associated with this conical structure enables one to understand the breaking of symmetries. Although the results are described for pure gravity, they may be extended to classes of fields coupled to gravity, such as gauge theories. Since most of the known solutions of Einstein's equations have Killing symmetries, the study of how these symmetries are broken by small perturbations takes on considerable theoretical significance

    The structure of the space of solutions of Einstein's equations. I. One Killing field.

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    This paper deals with globally hyperbolic solutions of the vacuum Einstein equations in a neighborhood of spacetimes that have a compact Cauchy surface of constant mean curvature. The first part of paper deal with solutions which have a single Killing vector field. Part II of the paper will then deal with the case of several Killing fields and general applications to mechanics

    Effect of simultaneous vehicle crossings on the North American fatigue correction factors

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    The Swiss design code (SIA) model for fatigue design is less simplistic than the North American codes. Indeed, the definition of the fatigue correction factor is given by a multiplication of four factors which take into account the type of bridge and the type of traffic. The fourth factor takes into account the traffic on several lanes, in order to deal with the effect of simultaneous vehicle crossings. The North American fatigue correction factor is equal to 0.52 or 0.75 for the Canadian and the AASHTO (American) codes respectively and is a constant for all cases. The aim of this work is to demonstrate that this simplistic definition of the fatigue correction factor is not adequate and, among others, does not take into account the effect of simultaneous vehicle crossings
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