Group theory and unification of forces: Application to ‘non-universal’ gaugino masses

We will give an overview on how to embed the Standard Model (SM), based on SU(3) × SU(2) × U(1), within larger groups. We will review the different chains one follows when spontaneously breaking SO(10) down to the SM. Finally, We shall discuss the question of non-universal gaugino masses in supersymmetric SO(10) theories.