Methods_for_simulation_of_dark_matter_dynamics_in_cosmology.pdf (1.07 MB)
Methods for simulation of dark matter dynamics in cosmology
presentation
posted on 2019-05-15, 00:22 authored by Emily KendallEmily Kendall, Mateja GosencaMateja GosencaWhile dark matter accounts for approximately 85% of the matter content of the observable
universe, its fundamental nature is one of the most important mysteries of modern physics. Many
different theories of dark matter have been proposed. We are studying ultra-light dark matter, a
scenario in which the dark matter particle is far lighter than any particle currently known to have a
non-zero mass. The behaviour of ultra-light dark matter is governed by the “Schroedinger-Poisson
equations”. We will introduce PyUltraLight, the code we have developed at the University of
Auckland to solve this system of coupled partial differential equations. PyUltraLight is written in
Python and can run inside a Jupyter notebook; it is currently the only freely shared, open-source
Schroedinger-Poisson solver available to astrophysicists. We are now using PyUltraLight to study
galaxy formation and galaxy-galaxy interactions in a universe with ultra-light dark matter.
One of the main challenges we are now facing is the need to simultaneously simulate large
physical volumes while resolving dynamics on small scales, e.g. in the central regions of the
galaxies or the detailed dynamics of galactic mergers. Increasing spatial resolution across the
whole simulation is computationally expensive and we are developing a simulation tool that uses
adaptive mesh refinement (AMR), a standard technique used to tackle problems where a significant
proportion of the simulation volume is empty. AMR codes allow the resolution to be increased only
in the locations of greatest interest, on the basis of specified refinement criteria. We will describe
the numerical methods we are now developing to simulate dark matter dynamics and discuss some
recent results and future research directions.
ABOUT THE AUTHOR(S)
Emily Kendall is a PhD student under Richard Easther at the University of Auckland. Mateja
Gosenca is a Postdoctoral researcher in the cosmology group at the University of Auckland. Both
are working on the theory and computational modelling of ultra-light dark matter.