Dark Matter In Minimal Trinification
  We study an example of Grand Unified Theory (GUT), known as trinification, which was first introduced in 1984 by S.Glashow. This model has the GUT gauge group as $[SU(3)]^3$ with a discrete $\mathbb{Z}_3$ to ensure the couplings are unified at the GUT scale. In this letter we consider this trinification model in its minimal formulation and investigate its robustness in the context of cosmology. In particular we show that for a large set of the parameter space the model doesn't seem to provide a Dark Matter candidate compatible with cosmological data. 
Edoardo Di Napoli, Damien George, Mark Hertzberg, Falk Metzler and   Ethan Siegel