Entries by haushofer

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…

The Revival of Newton-Cartan Theory

It’s a calculation which you can find in any textbook on General Relativity (GR): when gravity is weak and does not vary with time, and when particles are traveling slowly with respect to the speed of light, GR becomes good old Newtonian gravity again. However, this is done at the level of equations of motion….