GRG Editor's Choice: Analytic analysis of irregular discrete universes

© SpringerJolin, Shan W. & Rosquist, Kjell, Analytic analysis of irregular discrete universes, Gen Relativ Gravit (2018) 50: 115.

Editor's Choice (Research Article)

First Online:  21 August 2018

"This article studies universe models with discrete matter sources distributed non-regularly (with and without clustering) and compares the results with similar studies where the matter sources are distributed on a regular lattice. The work is thorough, the paper is well written and the extension of earlier work to irregular matter distributions is important. In addition, some of the results are very interesting when comparing to the equivalent results in discrete universe models with masses distributed on a regular lattice."


In this work we investigate the dynamics of cosmological models with spherical topology containing up to 600 Schwarzschild black holes arranged in an irregular manner. We solve the field equations by tessellating the 3-sphere into eight identical cells, each having a single edge which is shared by all cells. The shared edge is enforced to be locally rotationally symmetric, thereby allowing for solving the dynamics to high accuracy along this edge. Each cell will then carry an identical (up to parity) configuration which can however have an arbitrarily random distribution. The dynamics of such models is compared to that of previous works on regularly distributed black holes as well as with the standard isotropic dust models of the FLRW type. The irregular models are shown to have richer dynamics than that of the regular models. The randomization of the distribution of the black holes is done both without bias and also with a certain clustering bias. The geometry of the initial configuration of our models is shown to be qualitatively different from the regular case in the way it approaches the isotropic model.

The authors: 

Shan William Jolin is a PhD student in the department of Nanostructure Physics at the KTH Royal Institute of Technology, Stockholm. 

Kjell Rosquist is Professor Emeritus in the Department of Physics at Stockholm University.

Jolin-Rosquist © Author

GRG Editor's Choice:

In each volume of GRG, a few papers are marked as “Editor’s Choice”. The primary criteria is original, high quality research that is of wide interest within the community.