Ph.D positions available !!
Understanding the nature of dark matter, dark energy, the law of gravity or the origin of the structures we see today are among the most pressing questions in Cosmology.
I develop physical models and statistical methods for the large scale structure of the Universe in order to properly interpret observational data, and maximize the information that can be extracted from future surveys.
Here are a few examples of recent work:
Axion Dark Matter
If dark matter is in the form of very light, non-relativistic bosons such as axions, its large de Broglie wavelength (of Kiloparsec order) could alleviate the small-scale crisis of the popular Cold Dark Matter (CDM) model.
However, axions which acquired a mass through non-perturbative QCD effects are subject to an attractive self-interaction. This attractive force can counteract the “quantum pressure” induced by the strong delocalization and, furthermore, impact the stability of cosmic pancakes and filaments at low redshift.
Shot noise & Cosmic variance
Both are an essential ingredient to the analysis of galaxy survey data. In particular, recent work has shown that the shot noise induced the Dark Matter halos hosting the galaxies becomes increasingly sub-Poissonian at high mass.
This effect can be understood with a suitably modified version of the halo model, which leads to meaningful predictions for the shot noise contributions to halo clustering statistics while removing the unphysical white noise present in other statistics. Model predictions can be tested with large numerical simulations of the CDM cosmology.