Questions about some basic conceptions

[isospin]

Here I have some questions when reading a paper on supersymmetry. I am not familiar with those phrases below.
1, what is called 'rigid symmetry'?
2, does 'propagating degrees of freedom' mean degrees of freedom on shell?
3, when one says 'the gauge field are not dynamical', does it mean it has no degree of freedom on shell?

Thanks.

 

[nrqed]

Here I have some questions when reading a paper on supersymmetry. I am not familiar with those phrases below.
1, what is called 'rigid symmetry'?

I think this is used only in the context of SUSY.
It's another name for "global supersymmetry", i.e. the SUSY parameter does not depend on spacetime.

2, does 'propagating degrees of freedom' mean degrees of freedom on shell?

I think so.

3, when one says 'the gauge field are not dynamical', does it mean it has no degree of freedom on shell?

Thanks.

Are you sure you don't mean "auxiliary field" instead of gauge field? An auxiliary field is not dynamical because, as you said, it has no on-shell degrees of freedom.