Matter parity as the origin of scalar Dark Matter

We extend the concept of matter parity $P_M=(-1)^{3(B-L)}$ to non-supersymmetric theories and argue that $P_M$ is the natural explanation to the existence of Dark Matter of the Universe. We show that the non-supersymmetric Dark Matter must be contained in scalar 16 representation(s) of $SO(10),$ thus the unique low energy Dark Matter candidates are $P_M$-odd complex scalar singlet(s) $S$ and inert scalar doublet(s) $H_2.$ We have calculated the thermal relic Dark Matter abundance of the model and shown that its minimal form may be testable at LHC via the SM Higgs boson decays $H_1\to DM DM.$ The PAMELA anomaly can be explained with the decays $DM\to \nu l W$ induced via seesaw-like operator which is additionally suppressed by Planck scale. Because the SM fermions are odd under matter parity too, the DM sector is just our scalar relative.