23 research outputs found

    An Algorithm for the Simulations of the Magnetized Neutron Star Cooling

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    The model and algorithm for the cooling of the magnetized neutron stars are presented. The cooling evolution described by system of parabolic partial differential equations with non-linear coefficients is solved using Alternating Direction Implicit method. The difference scheme and the preliminary results of simulations are presented.Comment: 6 pages, 4 figures, accepted to the European Physical Journal Web of Conferences as a contribution of the International Conference Mathematical Modeling and Computational Physics 2015 (High Tatra Mountains, Slovakia, July 13 - July 17, 2015, http://web.tuke.sk/mmcp/mmcp2015/

    Bayesian analysis of multimessenger M-R data with interpolated hybrid EoS

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    We introduce a family of equations of state (EoS)for hybrid neutron star (NS) matter that is obtained by atwo-zone parabolic interpolation between a soft hadronicEoS at low densities and a set of stiff quark matter EoSat high densities within a finite region of chemical potentialsμH < μ < μQ. Fixing the hadronic EoS as the APRone and choosing the color-superconducting, nonlocal NJLmodel with two free parameters for the quark phase, we performBayesian analyses with this two-parameter family ofhybrid EoS. Using three different sets of observational constraintsthat include the mass of PSR J0740+6620, the tidaldeformability for GW170817, and the mass-radius relationfor PSR J0030+0451 from NICER as obligatory (set 1), whileset 2 uses the possible upper limit on themaximummass fromGW170817 as an additional constraint and set 3 instead ofthe possibility that the lighter object in the asymmetric binarymerger GW190814 is a neutron star. We confirm that in anycase, the quark matter phase has to be color superconductingwith the dimensionless diquark coupling approximately fulfillingthe Fierz relation ηD = 0.75 and the most probablesolutions exhibiting a proportionality between ηD and ηV , thecoupling of the repulsive vector interaction that is requiredfor a sufficiently largemaximummass.We used theBayesiananalysis to investigate with the method of fictitious measureaments the consequences of anticipating different radii for themassive 2 M PSR J0740+6220 for the most likely equationof state. With the actual outcome of the NICER radius measurementon PSR J0740+6220 we could conclude that for themost likely hybrid star EoS would not support a maximummass as large as 2.5 M so that the event GW190814 was abinary black hole merger.Fil: Ayriyan, Alexander. Laboratory of Information Technologies; Rusia. A. Alikhanyan National Laboratory; Armenia. Dubna State University; RusiaFil: Blaschke, David. University of Wroclaw; Polonia. Bogoliubov Laboratory for Theoretical Physics; Rusia. National Research Nuclear University; RusiaFil: Grunfeld, Ana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Alvarez Castillo, D. E.. Bogoliubov Laboratory for Theoretical Physics; Rusia. Henryk Niewodniczanski Institute of Nuclear Physics; PoloniaFil: Grigorian, H.. A. Alikhanyan National Laboratory; Armenia. Yerevan State University; Armenia. Laboratory of Information Technologies; RusiaFil: Abgaryan, V.. Laboratory of Information Technologies; Rusia. A. Alikhanyan National Laboratory; Armenia. Peoples’ Friendship University of Russia; Rusi

    Experimental and numerical study of properties of nematic liquid crystal waveguide structures

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    Nematic liquid crystal optical waveguide structures were studied by the numeric simulation and experimentally. Two types of optical smoothly-irregular waveguide structures promising for application in telecommunications and control systems are studied by numerical simulation and experimentally: liquid thin waveguide lens and thin film generalised waveguide Luneburg lens. The dependence of attenuation coefficient (optical losses) of the waveguide modes and the effective sizes (correlation radii) of the quasi-stationary irregularities of the liquid-crystal layer on the linear polarization of the incident laser radiation and the presence of pulse-periodic electric field were experimentally observed. An estimate is made of the correlation radii of liquid-crystal waveguide quasi-stationary irregularities. The observed decrease in the attenuation coefficient of the waveguide modes and the effective sizes of irregularities in the liquid-crystal layer, when the external electric field is switched on, explained by the effect of the decrease in the fluctuations correlation radii of the local orientation of the molecules of the liquid crystal. The obtained results are undoubtedly important for further research of dynamic processes inside non stationary waveguide liquid crystal layers, both from the theoretical point of view for understanding kinetic processes in the liquid crystals, and with practical, - in the organization and carrying out suitable experimental researches. © 2018 IEEE

    An Algorithm for the Simulation of the Magnetized Neutron Star Cooling

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    A model and algorithm for the cooling of the magnetized neutron stars are presented. The cooling evolution described by a system of parabolic partial differential equations with non-linear coeffcients is solved using the Alternating Direction Implicit method. A difference scheme and the preliminary results of simulations are presented

    Time-course of aberrations and their distribution: impact of LET and track structure

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    The biological response to high linear energy transfer (LET) radiation differs considerably from that to low LET radiation and this has been attributed to differences in the spatial energy deposition of both radiation qualities. In the case of X-rays the energy is deposited uniformly within the cell nucleus and produces damages in a purely stochastic manner. In contrast, for particles the energy is deposited inhomogeneously along the ion trajectory and the local dose decays with the square radial distance from the center of the track. This nonuniformity affects the yield and the distribution of aberrations among cells. Moreover, after high LET exposure a relationship between the aberration yield and cell cycle delay was observed. In this study, we present a detailed analysis of the distribution of aberrations in human lymphocytes reaching mitosis at early and later times after low and high LET exposure. Aberration data were fit to stochastic distributions demonstrating that the delay is related to the number of particle traversals per cell nucleus. To further elucidate this relationship, we introduce a Monte Carlo phenomenological model which incorporates the number of particle hits per nucleus. This value was derived by fitting theoretical distributions to the experimental data. Additionally, the probability that a cell traversed by a particle reaches mitosis at a given time was calculated. The analysis of biological data and numerical simulations clearly show the impact of the track structure on the formation of chromosome aberrations and their distribution among cells
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