A model of Yang-Mills interactions and gravity in terms of the Clifford
algebra Cl(0,6) is presented. The gravity and Yang-Mills actions are formulated
as different order terms in a generalized action. The feebleness of gravity as
well as the smallness of the cosmological constant and theta terms are
discussed at the classical level. The invariance groups, including the de
Sitter and the Pati-Salam SU(4) subgroups, consist of gauge transformations
from either side of an algebraic spinor. Upon symmetry breaking via the Higgs
fields, the remaining symmetries are the Lorentz SO(1,3), color SU(3),
electromagnetic U(1)_EM, and an additional U(1). The first generation leptons
and quarks are identified with even and odd parts of spinor idempotent
projections. There are still several shortcomings with the current model.
Further research is needed to fully recover the standard model results.Comment: 20 pages, to appear in Advances in Applied Clifford Algebra
