In electromagnetism, the **Lorenz gauge**, **Lorentz Condition** or **Lorenz gauge condition** is a partial gauge fixing of the electromagnetic vector potential. The condition is that ??. This does not completely fix the gauge: one can still make a gauge transformation where is a harmonic scalar function (that is, a scalar function satisfying , the equation of a massless scalar field).

The **Lorenz condition** is used to eliminate the redundant spin-0 component in the (1/2,1/2) representation of the Lorentz group. It is equally used for massive spin-1 fields where the concept of gauge transformations does not apply at all.

The **Lorenz condition** is named after Ludvig Lorenz. It is a **Lorentz invariant condition**, and is frequently called the "**Lorentz condition**" because of confusion with Hendrik Lorentz, after whom Lorentz covariance is named. Wikipedia, Lorentz Condition

See Also

**Bearden on Tesla and EM Source Charge** discussion
**Lorenz condition**
**Hendrik Lorentz**
**Lorentz Force**
**Ludvig Lorenz**