A physically consistent, discrete $n$-body model

A Consistent Discrete Version of a Non - Autonomous Sirvs Model

A discrete non-autonomous SIRVS model with general incidence is obtained from a continuous model by applying Mickens non-standard discretization method. Conditions for the permanence and extinction of the disease and the stability of diseasefree solutions are obtained. It is also proved that, if the time step is sufficiently small, when we obtain extinction (respectively permanence) for the con...

A New Consistent Discrete-velocity Model for the Boltzmann Equation

This paper discusses the convergence of a new discrete-velocity model to the Boltz-mann equation. First the consistency of the collision integral approximation is proved. Based on this we prove the convergence of solutions for a modiied model to DiPerna-Lions solutions of the Boltz-mann equation. As a test numerical example, the solutions to the discrete problems are compared to the exact solut...

A Physically Consistent Implicit Viscosity Solver for SPH Fluids

In this paper, we present a novel physically consistent implicit solver for the simulation of highly viscous fluids using the Smoothed Particle Hydrodynamics (SPH) formalism. Our method is the result of a theoretical and practical in-depth analysis of the most recent implicit SPH solvers for viscous materials. Based on our findings, we developed a list of requirements that are vital to produce ...

A Physically Consistent Model for X-ray Emission by Seyfert 2 Galaxies Demonstrated on Ngc 1068

Preliminary analysis of the X-ray spectrum of NGC 1068 obtained by the RGS spectrometer on board XMM-Newton is presented. A physically consistent model is developed in order to quantitatively describe the reprocessing of the central AGN continuum source into the discrete X-ray emission observed in Seyfert 2 galaxies. All the important atomic processes are taken into account, including photoexci...

Dynamics of a discrete-time plant-herbivore model