Pure Gauge
A pure gauge is the set of field configurations obtained by a gauge transformation on the null field configuration. So it is a particular "gauge orbit" in the field configuration's space.
In the abelian case, where, the pure gauge is the set of field configurations for all f(x).
Read more about this topic: Regauging
Famous quotes containing the word pure:
“The pure serene of memory in one man,—
A ripple widening from a single stone
Winding around the waters of the world.”
—Theodore Roethke (1908–1963)