We consider a two-step freeze-in mechanism of a singlet fermionic dark matter (DM) $\chi$ in a gauged $U(1)_{B-3L_i}$, $i \in \{e,\mu,\tau\}$, extension of the Standard model (SM). The DM communicates with the SM only through flavorful vector-portal $Z_{B3L}$ due to its non-trivial charge $x$ under $U(1)_{B-3L_i}$, which also guarantees the stability of the DM over the age of the Universe for...
Ultralight particles are well-motivated in many physical theories beyond Standard Model of particle physics. They can also be Dark Matter candidates. If these ultralight fields couple to standard model particles, they would show as additional signals with characteristic features. We show future space-based gravitational-wave interferometry can serve as a sensitive method to detect these light...
