Dark Matter Detection in Space

We live in interesting times: we know dark matter exists, and we now know how much. At the same time, we have very little idea what it is, other than that it can’t be any known particle. Cosmology therefore provides the longawaited quantitative evidence for new particle physics. The dark matter problem is arguably our strongest beacon, an unambiguous and fundamental, yet approachable, problem pointing us toward promising directions at the frontier. As with most frontiers, the dark matter landscape is populated by a variety of colorful characters: axions [1,2,3], neutralinos [4,5], Q balls [6], wimpzillas [7], axinos [8], self-interacting dark matter [9], fuzzy dark matter [10], annihilating dark matter [11], Kaluza-Klein dark matter [12,13], superWIMP dark matter [14,15], and many others. To bring some order to the following discussion, if not to the field, we therefore need a guiding principle.