- #1

silverwhale

- 84

- 2

I am learning QFT using Sidney Colemans lecture notes (and the Peskin Schroeder book). They can be found here:

http://arxiv.org/abs/1110.5013

Now, in page 40, he introduces in the paragraph Symmetries and Conservation laws some definitions which I don't quite understand.

First he writes,

[tex] q^a(t) \rightarrow q^a(t,\lambda). [/tex]

For a transformation of the generalized coordinates.

Second he defines,

[tex]Dq^a \equiv \frac{\partial q^a}{\partial \lambda}. [/tex]

Now my question is just, does anybody recognize these definitions? is there some book where I can find, learn and play with them?

I never saw such a definition for a symmetry.

Well, if no literature exsits, can anybody explain to me what this derivative means?

Thanks alot!