New tests of physics with constrained large-scale structure simulations

Typical simulations of galaxy formation adopt random phases for the primordial density perturbations and therefore produce structures with specified statistical properties but arbitrary positions in space.

In contrast, "constrained" simulations match the matter distribution of the actual local Universe, allowing a one-to-one mapping between objects in the simulation and observed galaxies and structures.

The student will leverage a suite of constrained N-body simulations called CsiBORG (Bartlett et al. 2021) to devise and carry out novel investigations of astrophysical models.

This may include testing semi-analytic galaxy formation models, searching for correlations between the evolution of dark matter and visible matter over cosmic time, developing or exploiting a new method for identifying voids in the local Universe (Desmond et al. 2022), and/or quantifying potential bias in the locally measured expansion rate of the Universe due to nearby structure.

There is also scope for the student to run their own constrained simulations, for example with the addition of hydrodynamics and radiative transfer to explore the reionization history of the local Universe, and/or to constrain the distribution of neutral/molecular hydrogen in the local Universe.