Strongly Interacting Light Dark Matter

In the presence of approximate global symmetries that forbid relevantinteractions, strongly coupled light Dark Matter (DM) can appear weakly coupledat small energy and generate a sizable relic abundance. Fundamental principleslike unitarity restrict these symmetries to a small class, where the leadinginteractions are captured by effective operators up to dimension-8. Chiralsymmetry, spontaneously broken global symmetries and non-linearly realizedsupersymmetry are examples of this. Their DM candidates (composite fermions,pseudo Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHCmissing-energy searches.