(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Hi,

This question is about Lorentzgroups. In my course of Relativity, we've seen a very little about representations of complete Lorentz groups but there are two little exercises, which we can do, but I do not understand what should be checked, not even how to start this.

The question is the following:

A/Does the Lagrangian L = i u*^{Adot} \partial_{A Adot} u^{Adot} (with u^A a spinor field and u* a conjugated spinor) form a scalar under the complete Lorentzgroup?

B/What about the Lagrangian L = F_{mu nu} F*^{mu nu}, and I suppose this F is the Electromagnetic Maxwell Tensor (http://en.wikipedia.org/wiki/Electromagnetic_tensor)

2. Relevant equations

/

3. The attempt at a solution

Don't even understand the meaning of "a scalar under the complete Lorentzgroup".

Thanks for any help you can offer and a Merry Christmas to all of you!

Trinitiet

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

Dismiss Notice

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!

# Spinors and Lorentzgroups: representation of the complete Lorentzgroup?

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