First I will briefly review the approach of simplified models for dark matter phenomenology. Then I will discuss non-standard strategies in dark matter model building, characterized by a feeble coupling between the dark matter and the SM particles, which lead to novel and exotic signatures at the LHC in terms of longlived particles. I will explore the possible mechanisms through which DM can be produced during the early universe in these models. In particular, by studying simple benchmark cases, I will emphasise the generic interplay between displaced signatures at the LHC and cosmology for dark matter candidates whose relic abundance is obtained through the freeze-in mechanism.
org: FRANCESCHINI Roberto