Axions and axion-like particles (ALPs) remain compelling dark matter (DM) candidates, provided that the associated Peccei-Quinn (PQ) symmetry breaking scale is sufficiently large to ensure cosmological stability. In this talk, I will explore a novel framework in which ALPs possess flavor-violating (FV) couplings to Standard Model (SM) quarks, allowing them to be produced via freeze-in in the...
Ultralight scalar fields that interact with Standard Model particles through electromagnetic and electrophilic couplings can be efficiently sourced by compact stars, leading to the emergence of long-range forces within binary systems. In certain regimes, these scalars may also be emitted from the stars, giving rise to distinctive observational signatures. In this talk, I will present...
