Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article A Metric for Gravitational Collapse Around a Schwarzschild Black Hole(World Scientific Publishing, 2023) Erdem, Recai; Demirkaya, Betül; Gültekin, KemalWe consider the problem of gravitational collapse of a fluid under the effect of a small Schwarzschild black hole (e.g. a primordial one). We assume the fluid initially may be approximated by a uniform homogeneous dust. Starting from this configuration we obtain a class of metrics under some physically justified assumptions. We find that the metric we obtain includes the dust collapse as a subcase. After discussing some basic properties of the solution, we discuss the case of dust collapse in more detail. We find that the radial and tangential pressures outside the horizon may take positive or negative values depending on the values of the parameters.Correction Correction To: “curved Space and Particle Physics Effects on the Formation of Bose–einstein Condensation Around a Reissner–nordstrøm Black Hole”(Springer, 2022) Erdem, Recai; Demirkaya, Betül; Gültekin, KemalAfter this correction Fig. 1 in [1] is replaced by Fig. 1 above which is essentially the same as the one in [1]. Figure 2 in [1] now becomes irrelevant. Figure 3 in [1] is replaced by Fig. 2 above which is essentially the same as the one in [1].Article Citation - WoS: 2Citation - Scopus: 2Curved Space and Particle Physics Effects on the Formation of Bose-Einstein Condensation Around a Reissner-Nordstrom Black Hole(Springer, 2021) Erdem, Recai; Demirkaya, Betül; Gültekin, KemalWe consider two scalar fields interacting through a chi*chi phi*phi term in the presence of a Reissner-Nordstrom black hole. Initially, only chi particles are present. We find that the produced phi particles are localized in a region around the black hole and have a tendency toward condensation provided that phi particles are much heavier than the chi particles. We also find that such a configuration is phenomenologically viable only if the scalars and the black hole have dark electric charges.Article Citation - WoS: 607Citation - Scopus: 736Black Holes, Gravitational Waves and Fundamental Physics: a Roadmap(IOP Publishing, 2019) Barack, Leor; Cardoso, Vitor; Nissanke, Samaya; Sotiriou, Thomas P.; Askar, Abbas; Belczynski, Chris; Erdem, RecaiThe grand challenges of contemporary fundamental physics dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'.Article Citation - WoS: 22Citation - Scopus: 26Search for Black Holes and Other New Phenomena in High-Multiplicity Final States in Proton-Proton Collisions at Root S=13 Tev(Elsevier Ltd., 2017) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Karapınar, Güler; CMS CollaborationA search for new physics in energetic, high-multiplicity final states has been performed using proton-proton collision data collected with the CMS detector at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 2.3 fb(-1). The standard model background, dominated by multijet production, is determined exclusively from control regions in data. No statistically significant excess of events is observed. Model-independent limits on the product of the cross section and the acceptance of a new physics signal in these final states are set and further interpreted in terms of limits on the production of black holes. Semiclassical black holes and string balls with masses as high as 9.5 TeV, and quantum black holes with masses as high as 9.0 TeV are excluded by this search in the context of models with extra dimensions, thus significantly extending limits set at a center-of-mass energy of 8 TeV with the LHC Run 1 data. (c) 2017 The Author(s). Published by Elsevier B.V.Article Citation - WoS: 13Citation - Scopus: 13Thermodynamics of Regular Black Holes With Cosmic Strings(Springer, 2018) Bayraktar, Ceren H.In this article, the thermodynamics of regular black holes with a cosmic string passing through them is studied. We will observe that the string has no effect on the temperature as well as on the relation between entropy S and horizon area A.Article Citation - WoS: 61Citation - Scopus: 39Search for Microscopic Black Holes in Pp Collisions at ?s=8 Tev(Springer Verlag, 2013) CMS Collaboration; Karapınar, GülerA search for microscopic black holes and string balls is presented, based on a data sample of pp collisions at √s=8 TeV recorded by the CMS experiment at the Large Hadron Collider and corresponding to an integrated luminosity of 12 fb-1. No excess of events with energetic multiparticle final states, typical of black hole production or of similar new physics processes, is observed. Given the agreement of the observations with the expected standard model background, which is dominated by QCD multijet production, 95% confidence level limits are set on the production of semiclassical or quantum black holes, or of string balls, corresponding to the exclusions of masses below 4.3 to 6.2 TeV, depending on model assumptions. In addition, model-independent limits are set on new physics processes resulting in energetic multiparticle final states. [Figure not available: see fulltext.] © 2013 CERN for the benefit of the CMS collaboration.Article Citation - WoS: 29Citation - Scopus: 41Soliton resonances in a generalized nonlinear Schrödinger equation(IOP Publishing Ltd., 2008) Pashaev, Oktay; Lee, Jyh Hao; Rogers, ColinIt is shown that a generalized nonlinear Schrödinger equation proposed by Malomed and Stenflo admits, for a specific range of parameters, resonant soliton interaction. The equation is transformed to the 'resonant' nonlinear Schrödinger equation, as originally introduced to describe black holes in a Madelung fluid and recently derived in the context of uniaxial wave propagation in a cold collisionless plasma. A Hirota bilinear representation is obtained and soliton solutions are thereby derived. The one-soliton solution interpretation in terms of a black hole in two-dimensional spacetime is given. For the two-soliton solution, resonant interactions of several kinds are found. The addition of a quantum potential term is considered and the reduction is obtained to the resonant NLS equation. © 2008 IOP Publishing Ltd.Article Citation - WoS: 91Citation - Scopus: 91Resonance Solitons as Black Holes in Madelung Fluid(World Scientific Publishing Co. Pte Ltd, 2002) Pashaev, Oktay; Lee, Jyh HaoEnvelope solitons of the Nonlinear Schrödinger equation (NLS) under quantum potential's influence are studied. Corresponding problem is found to be integrable for an arbitrary strength, s ≠ 1, of the quantum potential. For s < 1, the model is equivalent to the usual NLS with rescaled coupling constant, while for s > 1, to the reaction-diffusion system. The last one is related to the anti-de Sitter (AdS) space valued Heisenberg model, realizing a particular gauge fixing condition of the (1 + 1)-dimensional Jackiw-Teitelboim gravity. For this gravity model, by the Madelung fluid representation we derive the acoustic form of the space-time metric. The space-time points, where dispersion changes the sign, correspond to the event horizon, while the soliton solution to the AdS black hole. Moving with the above bounded velocity, it describes evolution on the one sheet hyperboloid with nontrivial winding number, and creates under collision, the resonance states which we study by the Hirota bilinear method.Conference Object Citation - WoS: 6Citation - Scopus: 6Soliton Resonances, Black Holes and Madelung Fluid(Taylor and Francis Ltd., 2001) Pashaev, Oktay; Lee, Jyh HaoThe reaction-diffusion system realizing a particular gauge fixing condition of the Jackiw-Teitelboim gravity is represented as a coupled pair of Burgers equations with positive and negative viscosity. For acoustic metric in the Madelung fluid representation the space-time points where dispersion change the sign correspond to the event horizon, while shock soliton solutions to the black holes, creating under collision the resonance states.