26 research outputs found
Model of the Phase Transition Mimicking the Pasta Phase in Cold and Dense Quark-Hadron Matter
A simple mixed phase model mimicking so-called "pasta" phases in the
quark-hadron phase transition is developed and applied to static neutron stars
for the case of DD2 type hadonic and NJL type quark matter models. The
influence of the mixed phase on the mass-radius relation of the compact stars
is investigated. Model parameters are chosen such that the results are in
agreement with the observational constraints for masses and radii of pulsars.Comment: 6 pages, 4 figure
Performance Analysis of Effective Symbolic Methods for Solving Band Matrix SLAEs
This paper presents an experimental performance study of implementations of
three symbolic algorithms for solving band matrix systems of linear algebraic
equations with heptadiagonal, pentadiagonal, and tridiagonal coefficient
matrices. The only assumption on the coefficient matrix in order for the
algorithms to be stable is nonsingularity. These algorithms are implemented
using the GiNaC library of C++ and the SymPy library of Python, considering
five different data storing classes. Performance analysis of the
implementations is done using the high-performance computing (HPC) platforms
"HybriLIT" and "Avitohol". The experimental setup and the results from the
conducted computations on the individual computer systems are presented and
discussed. An analysis of the three algorithms is performed.Comment: 7 pages, 9 tables, 4 figure
Effective Methods for Solving Band SLEs after Parabolic Nonlinear PDEs
A class of models of heat transfer processes in a multilayer domain is
considered. The governing equation is a nonlinear heat-transfer equation with
different temperature-dependent densities and thermal coefficients in each
layer. Homogeneous Neumann boundary conditions and ideal contact ones are
applied. A finite difference scheme on a special uneven mesh with a
second-order approximation in the case of a piecewise constant spatial step is
built. This discretization leads to a pentadiagonal system of linear equations
(SLEs) with a matrix which is neither diagonally dominant, nor positive
definite. Two different methods for solving such a SLE are developed --
diagonal dominantization and symbolic algorithms.Comment: 4 pages, 1 figure, 1 tabl
Compact Stars in the QCD Phase Diagram
The book edition of the Universe Special Issue “Compact Stars in the QCD Phase Diagram” is devoted to the overarching aspects shared between heavy-ion collisions and compact star astrophysics in investigating the hadron-to-quark matter phase transition in the equation of state of strongly interacting matter in different regions of the phase diagram of QCD. It comprises 22 review and research articles that, together, will serve as a useful guide in educating both young and senior scientists in this emerging field that represents an intersection of the communities of strongly interacting matter theory, heavy-ion collision physics and compact star astrophysics
Parallel Algorithm for Solving TOV Equations for Sequence of Cold and Dense Nuclear Matter Models
We have introduced parallel algorithm simulation of neutron star configurations for set of equation of state models.The performance of the parallel algorithm has been investigated for testing set of EoS models on two computational systems. It scales when using with MPI on modern CPUs and this investigation allowed us also to compare two different types of computationa lnodes