Pure gauge
Pure gauge
Melvin E. Windsor
In <a href="Physics">Physics</a>, <b>pure gauge</b> is the set of field configurations obtained by a gauge transform on the null field configuration. So it is a particular "gauge orbit" in the field configuration's space. In the abelian case, where <nobr><font size=3><i>A</i>&nbsp;'<sub> <i> &#956;</i></sub> (<i>x</i>)  <font face='Arial Unicode MS,Code2000'>&#8594;</font>  <i>A</i><sub> <i> &#956;</i></sub> (<i>x</i>)+&nbsp;&#8706; <sub> <i> &#956;</i></sub> f (<i>x</i>)</font></nobr>, the pure gauge is the set of field configurations <nobr><font size=3><i>A</i>&nbsp;'<sub> <i> &#956;</i></sub> (<i>x</i>) =  &#8706; <sub> <i> &#956;</i></sub> f (<i>x</i>)</font></nobr> for all <i>f</i>(<i>x</i>).