Streams: A small, mesh-based look at large structure formation

Jack Morrice (University of Cape Town)

17 October 2018

Today, cosmology's N-body paradigm looks a bit like a power monopoly. The codes (GADGET, RAMSES... ) have huge computational overheads; descriptions of their underlying algorithms are old and hard to find, and the outputs of these codes are very difficult to analyse.

These factors make the study of cosmic large scale structure accessible only to those with easy access to a lot of supercomputer cores and a familiarity with old imperative programming languages like C and Fortran.

In this talk, we will look at Streams, a modest attempt to address these issues. Streams is a small package written for the Julia programming language that uses Lagrangian perturbation theory to significantly reduce overheads. It is also built from a computer geometry (mesh) perspective which makes it very well suited to studying the formation of folds and caustics in the dark matter fluid on a personal computer.