Fermionic Dark Matter: Physics, Astrophysics, and Cosmology

The nature of dark matter (DM) is one of the most relevant questions in modern astrophysics. We present a brief overview of recent results that inquire into the possible fermionic quantum nature of the DM particles, focusing mainly on the interconnection between the microphysics of the neutral fermions and the macrophysical structure of galactic halos, including their formation both in the linear and non-linear cosmological regimes. We discuss the general relativistic Ruffini-Arguelles-Rueda (RAR) model of fermionic DM in galaxies, its applications to the Milky Way, the possibility that the Galactic center harbors a DM core instead of a supermassive black hole (SMBH), the S-cluster stellar orbits with an in-depth analysis of the S2's orbit including precession, the application of the RAR model to other galaxy types (dwarf, elliptic, big elliptic, and galaxy clusters), and universal galaxy relations. All the above focus on the model parameters' constraints most relevant to the fermion mass. We also connect the RAR model fermions with particle physics DM candidates, self-interactions, and galactic observable constraints. The formation and stability of core-halo galactic structures predicted by the RAR model and their relations to warm DM cosmologies are also addressed. Finally, we provide a brief discussion of how gravitational lensing, dynamical friction, and the formation of SMBHs can also probe the DM's nature.

Automated summary

This article provides an overview of recent research on the possible fermionic quantum nature of dark matter particles, focusing on the interconnection between the microphysics of neutral fermions and the macrophysical structure of galactic halos. The article discusses the application of the general relativistic RAR model of fermionic dark matter to the Milky Way and other galaxy types, as well as the constraints on model parameters and the connection to particle physics dark matter candidates. Additionally, the article addresses the formation and stability of core-halo galactic structures predicted by the RAR model and their relation to warm dark matter cosmologies, and discusses how gravitational lensing, dynamical friction, and the formation of supermassive black holes can probe the nature of dark matter.