It is said that : electrodynamics is a gauge theory for U(1) gauge group . what is its physical concept?(adsbygoogle = window.adsbygoogle || []).push({});

Mathematically it mean that the field is invariant under transformation under components of U(1) group, that we can show them with e[itex]^{i\theta}[/itex] and we can consider them as a phase angle . so does it mean that if we product a field with a phase angle , the physics of problem doesn't change ? if it is true so what about teleparallel gravity that consider gravity as a gauge theory for translation group ? is it mean that the physics of problem doesn't change with small translation of spacetime points ? nad if is it true so it should be a gauge group for electrodynamics too.

Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Concept of gauge theory ?

**Physics Forums | Science Articles, Homework Help, Discussion**