A light in the dark: Unifying the modelling of baryonic effects for probes of large scale structures

Cosmology is a new and fast growing field, owing this growth to both new technology and statistical methods in imaging and data processing. It is believed that we can explain the cosmology of the entire Universe using a handful of parameters through the standard cosmological model. This model has been very successful in predicting the distribution of galaxies and matter, as well as very early measurements of cosmic microwave background radiation.

As the volume of data is growing we are starting to see cracks in this simple picture of the Universe, through tensions between the results of different observational analyses. The most prominent components of this model are dark: dark matter and dark energy, which are poorly understood. Therefore, I see these cracks as a silver lining which may point us to a better model and a deeper understanding of the nature of dark matter and dark energy.

Although the universe is dominated by the dark sector, we cannot directly probe it. We tend to use light to trace darkness. The probes of large scale structures in particular use light emitted from thousands or millions of faraway galaxies to trace the matter distribution and understand structure growth and evolution.

These structures are mainly made up of dark matter but they host the regular matter (baryons) that emits light. Baryons follow complicated physics, aside from gravity they are impacted by heating/cooling, pressure and explosions. To really understand the dark Universe we need to first understand how these complex physics impact the light that is emitted from baryons.

With this project my team will explore state-of-the-art simulations of the Universe to understand the distribution of galaxies and how they connect to the underlying dark matter structures. We will then bring these physical effects together under a single framework and apply it to the current and near future cosmological probes. We will then establish whether the tensions originate from poor modelling of baryonic effects or if they are due to the breakdown of the standard cosmological model!