Title: Freeze-in Dark Matter and Lifetime Frontier


Abstract: In the context of a well-motivated gauged U(1) extension of the Standard Model,
I will introduce a non-thermal dark matter whose interaction is too weak to allow it to be
in thermal equilibrium with the Standard Model particles and its relic density is determined
by the “freeze-in” mechanism through a light “mediator.” I will discuss a complementarity
between the cosmological constraint on this dark matter physics and the planned/proposed
Lifetime Frontier experiments to search for a ling-lived light mediator.