We present a novel, data-driven analysis of Galactic dynamics, using unsupervised machine learning -- in the form of density estimation with normalizing flows -- to learn the underlying phase space distribution of 6 million nearby stars from the Gaia DR3 catalog. Solving the collisionless Boltzmann equation with the assumption of approximate equilibrium, we calculate -- for the first time ever...
The accretion of dark matter around the black hole could lead to the formation of surrounding halo. Such a dark matter dressed black hole can leave characteristic imprints in the observations including gamma-ray, gravitational lensing and gravitational waves. In this talk, I will talk several observational phenomena on the black hole with dark matter dress.
In a secluded dark sector scenario, the connection between the visible and the dark sector can be established through a portal coupling and its presence opens up the possibility of non-adiabatic evolution of the dark sector. Here, we have considered a U(1)Lμ−Lτ⊗U(1)X extension of the standard model (SM) to study the evolution of a decoupled dark sector in a...
Our investigation focuses on determining the mass range and free-streaming length scale of dark matter resulting from heavy objects' non-thermal decay. These objects may be dominant or sub-dominant at the time of decay. Our findings indicate that the resulting dark matter can be exceptionally light, possibly below the keV scale, and still comply with the Lyman-α constraints on free-streaming...
Dark matter (DM) may be comprised of axionlike particles (ALPs) with couplings to photons and the standard model fermions. We study photon signals arising from cosmic ray (CR) electron scattering on background ALPs. For a range of masses we find that these bounds can place competitive new constraints on the ALP-electron coupling. In addition to current Fermi constraints, we also consider...
