We present a rigorous mathematical proof of the unique direct sum decomposition of the Cl(1,9) Clifford algebra using idempotent elements. This decomposition reveals a rich algebraic structure including a central subalgebra isomorphic to Cl(1,3), corresponding to Minkowski spacetime. The results provide a formal framework potentially relevant to geometric and algebraic approaches in mathematical physics and theoretical cosmology.
S. A. Omel’chenko (Fri,) studied this question.