## General Relativity as a Gauge Theory

The fundamental interactions of the Standard Model are described by Yang-Mills theory. This is a gauge theory, which means the following: (1) Choose a group of global i.e. spacetime-independent symmetries and write down the Lie algebra which generates it, (2) ‘Gauge’ this algebra, i.e. make the symmetries spacetime-dependent, and (3) Introduce gauge fields which compensate…