Exploring the dark matter landscape through its momentum distribution

Objective

Dark matter (DM) exists, probably in the form of stable particles. It makes up about 25% of the energy budget of the Universe. Despite decades of research, its exact nature is still unknown. In the typical theoretical treatment, we impose features on the DM phase-space distribution (PSD), limiting the type of DM we can study. Thus, advancing the search for DM may require DM studies at the PSD-level (i.e. without imposing assumptions on the PSD), allowing us to study particle DM in more detail, make accurate predictions consistently, and consider atypical scenarios, expanding our theoretical search and enabling us to look for DM utilizing our full experimental reach, from particle experiments (e.g. LHC) to telescopes (e.g. JWST). My two objectives aim to fill significant gaps by studying DM at the PSD level. Objective 1 aims to quantify the impact of several reaction types on the DM PSD and relevant quantities, by computing the DM PSD for specific interactions between DM and other particles. This will provide accurate computation of observables, serving also as model-independent results. It will also allow for comparison with results obtained from the typical treatment, quantifying its limitations. Objective 2 aims to perform PSD-level analyses of DM models, providing valid predictions beyond the typical cases. By taking into account searches across multiple scales, from galaxy formation to direct-detection experiments, we will assess the potential of these DM models to be observed as well as address open astrophysical and cosmological problems connected to DM. The impact of this project lie in the improvement of the theoretical treatment of DM, including the development of methods for computing the DM PSD, quantification of the limitations of the typical approach, and improvement of the experimental constraints -- especially for previously ignored cases. The outcomes will enable further theoretical studies and potentially propose new ways of looking for DM.