Dark Matter and Gauge Coupling Unification in Non-SUSY SO(10) Grand Unified Models

The stability of dark matter is naturally explained if there is an additional U(1) symmetry which is spontaneously broken to a discrete symmetry at a high-energy scale. Such a framework is realized in the context of the SO(10) grand unification. In this work, we discuss dark matter models in the non-supersymmetric SO(10) grand unified models in which the stability of dark matter is assured by this mechanism. We find that the requirement of gauge coupling unification with a sufficiently high unification scale to evade the proton decay constraints plays an important role in selecting viable candidates. Some of the dark matter models can be tested in future dark matter direct searches and proton decay experiments.