9 research outputs found

    A Quintessence Problem in Self-interacting Brans-Dicke Theory

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    A quintessence scalar field in self-interacting Brans-Dicke theory is shown to give rise to a non-decelerated expansion of the present universe for open, flat and closed models. Along with providing a non-decelerating solution, it can potentially solve the flatness problem too.Comment: 8 Latex pages, No figure, Revtex styl

    A Quintessence Problem in Brans-Dicke Theory with Varying Speed of Light

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    It is shown that minimally coupled scalar field in Brans-Dicke theory with varying speed of light can solve the quintessence problem and it is possible to have a non-decelerated expansion of the present universe with BD-theory for anisotropic models without any matter.Comment: 8 Latex pages, 6 figures, Revtex styl

    Gravitational Collapse in Higher Dimensional Husain Space-Time

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    We investigate exact solution in higher dimensional Husain model for a null fluid source with pressure pp and density ρ\rho are related by the following relations (i) p=kρp=k\rho, (ii) p=kρB(v)ραp=k\rho-\frac{B(v)}{\rho^{\alpha}} (variable modified Chaplygin) and (iii) p=kραp=k\rho^{\alpha} (polytropic). We have studied the nature of singularity in gravitational collapse for the above equations of state and also for different choices of the of the parameters kk and BB namely, (i) k=0k=0, B=B= constant (generalized Chaplygin), (ii) B=B= constant (modified Chaplygin). It is found that the nature of singularity is independent of these choices of different equation of state except for variable Chaplygin model. Choices of various parameters are shown in tabular form. Finally, matching of Szekeres model with exterior Husain space-time is done.Comment: 12 latex pages, No figure, RevTex styl

    An overview of Indian research in schizophrenia

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    The Indian Journal of Psychiatry published three articles in its first issue way back in 1958. Since then, it has steadily published more than 200 papers on one or the other aspect of schizophrenia. From rudimentary research methodology and descriptive approach, schizophrenia research, as published in the Journal, seems to have come of age with more and more sophisticated research designs and methodologies. Our ardent researchers have made significant contributions in the understanding of this riddle called schizophrenia. Notable contributions have been made in the field of epidemiology, course and outcomes and phenomenology of this disorder. However, research in psycho-social rehabilitation of schizophrenia and related areas is sparse and sporadic. The need to conduct research that impacts health policies and planning of services for this disorder is evident and our researchers would do well to provide impetus in these areas

    Abstracts of National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020

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    This book presents the abstracts of the papers presented to the Online National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020 (RDMPMC-2020) held on 26th and 27th August 2020 organized by the Department of Metallurgical and Materials Science in Association with the Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, India. Conference Title: National Conference on Research and Developments in Material Processing, Modelling and Characterization 2020Conference Acronym: RDMPMC-2020Conference Date: 26–27 August 2020Conference Location: Online (Virtual Mode)Conference Organizer: Department of Metallurgical and Materials Engineering, National Institute of Technology JamshedpurCo-organizer: Department of Production and Industrial Engineering, National Institute of Technology Jamshedpur, Jharkhand, IndiaConference Sponsor: TEQIP-

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    International audienceAmong the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)BLU(1)_{B-L} gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)BLU(1)_{B-L} gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    ATLAS

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    % ATLAS \\ \\ ATLAS is a general-purpose experiment for recording proton-proton collisions at LHC. The ATLAS collaboration consists of 144 participating institutions (June 1998) with more than 1750~physicists and engineers (700 from non-Member States). The detector design has been optimized to cover the largest possible range of LHC physics: searches for Higgs bosons and alternative schemes for the spontaneous symmetry-breaking mechanism; searches for supersymmetric particles, new gauge bosons, leptoquarks, and quark and lepton compositeness indicating extensions to the Standard Model and new physics beyond it; studies of the origin of CP violation via high-precision measurements of CP-violating B-decays; high-precision measurements of the third quark family such as the top-quark mass and decay properties, rare decays of B-hadrons, spectroscopy of rare B-hadrons, and Bs0 B ^0 _{s} -mixing. \\ \\The ATLAS dectector, shown in the Figure includes an inner tracking detector inside a 2~T~solenoid providing an axial field, electromagnetic and hadronic calorimeters outside the solenoid and in the forward regions, and barrel and end-cap air-core-toroid muon spectrometers. The precision measurements for photons, electrons, muons and hadrons, and identification of photons, electrons, muons, τ\tau-leptons and b-quark jets are performed over η| \eta | < 2.5. The complete hadronic energy measurement extends over η| \eta | < 4.7. \\ \\The inner tracking detector consists of straw drift tubes interleaved with transition radiators for robust pattern recognition and electron identification, and several layers of semiconductor strip and pixel detectors providing high-precision space points. \\ \\The e.m. calorimeter is a lead-Liquid Argon sampling calorimeter with an integrated preshower detector and a presampler layer immediately behind the cryostat wall for energy recovery. The end-cap hadronic calorimeters also use Liquid Argon technology, with copper absorber plates. The end-cap cryostats house the e.m., hadronic and forward calorimeters (tungsten-Liquid Argon sampling). The barrel hadronic calorimeter is an iron-scintillating tile sampling calorimeter with longitudinal tile geometry. \\ \\Air-core toroids are used for the muon spectrometer. Eight superconducting coils with warm voussoirs are used in the barrel region complemented with superconducting end-cap toroids in the forward regions. The toroids will be instrumented with Monitored Drift Tubes (Cathode Strip Chambers at large rapidity where there are high radiation levels). The muon trigger and second coordinate measurement for muon tracks are provide
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