English

Initial data for general relativistic SPH with Centroidal Voronoi Tessellations

General Relativity and Quantum Cosmology 2013-11-26 v1

Abstract

In this work we present an alternative method to obtain a distribution of particles over an hyper surface, such that they obey a rest-mass density distribution ρ(xi)\rho(x^i). We use density profiles that can be written as ρ(x1,x2,x3)=ρ(x1)ρ(x2)ρ(x3)\rho(x^1,x^2,x^3)=\rho(x^1) \rho(x^2) \rho(x^3) in order to be able to use them as a probability density functions. We can find the relation between the chart xjx^j and a uniform random variable xˉj(0,1)\bar{x}^j \in (0,1), say F(xj)=xˉjF(x^j)=\bar{x}^j. Using the inverse of this function we relate a set of NN arbitrary number of points inside a cube with coordinates {xj=F1(xˉj)}\{ x^j =F^{-1}(\bar{x}^j)\} giving the position in order to get the density distribution ρ(xj)\rho(x^j). We get some noise due to the random distribution and we can notice that each time we relax the configuration on the cube we also get a better distribution of the desired physical configuration described with ρ(xj)\rho(x^j). This relaxation of the position of the particles in the cube has been performed a Lloyd's algorithm in 3D and we have used {\it Voro++} library in order to get the Voronoi tessellations.

Keywords

Cite

@article{arxiv.1311.6456,
  title  = {Initial data for general relativistic SPH with Centroidal Voronoi Tessellations},
  author = {Cruz Pérez Juan Pablo and González Cervera José Antonio},
  journal= {arXiv preprint arXiv:1311.6456},
  year   = {2013}
}
R2 v1 2026-06-22T02:14:37.967Z