  It has been recently pointed out by Arkani-Hamed and Dimopoulos that if the
universe is a landscape of vacua, and if therefore fine-tuning is not a valid
guidance principle for searching for physics beyond the standard model,
supersymmetric unification only requires the fermionic superpartners. We argue
that in that landscape scenario, the fermionic superpartners are not needed for
unification, which can be achieved in SO(10) either via a direct breaking to
the standard model at the grand unification scale or through an intermediate
gauge symmetry. In most minimal SO(10) models, the proton lifetime is long
enough to avoid the experimental bounds. These models are the truly minimal
fine-tuned extensions of the standard model in the sense proposed by Davoudiasl
et al..

High Energy Physics - Phenomenology;High Energy Physics - Theory