## Theories of the Grand Unification

*The following lectures took place at Moscow State University.*

*Lecturer: K. V. Stepanyantz*

### 1. The Standard Model of elementary particles and forces

The Standard Model of elementary particles and forces is built on top of the Yang-Mills non-abelian gauge theory. It makes use of the nonprime gauge group - a direct product of three prime groups \(SU(3)\times SU(2)\times U(1)\).