Re: hands-on gauge transformations

[Jack Uretsky <jlu@HEP.ANL.GOV>]

Hi all-
        So John's implicit question is: What is the definition of
"gauge transformation"?
        The question took me back to Wentzel's <Quantum Theory of
Fields>.  "Gauge transformations" were apparently introduced by Pauli,
Phys. Rev. 58, 716 (1940), and originate with phase transformations
of spinor fields in Quantum Mechanics.  The phase transformations
induce transformations of the vector potentials that correspond to
the electromagnetic fields.
        So unless someone can show that Pauli cites an earlier and
more restrictive use of the term, I will persist in my use of
"like a gauge transformation."
                                Regards,
                                        Jack

On Mon, 31 Jul 2000, John Denker wrote:

> At 01:05 PM 7/30/00 -0500, Jack Uretsky wrote:
> > Hi all-
> >         Interesting thought:  Changing the "zero" from which potential
> > is measured is like a gauge transformation.
>
> Yup, it's always nice to have a connection between
>    -- feet on the ground: moving the black lead of the voltmeter
>       from one node to another, and
>    -- head in the clouds:  gauge transformations.
>
> But...  why be so tentative?
>    -- Why say it "is like" a gauge transformation
>       rather than "is" a gauge transformation?
>    -- Is there a definition of gauge transformation under which
>       phi -> phi + const is not a full-fledged member?
>
> (Of course nobody is suggesting this is the only gauge transformation).