# Spin-One Klein Gordon Equation

Jogging-Joe
TL;DR Summary
The spin zero Klein Gordon equation is commonly discussed. How about the spin one Klein Gordon Equation?
What is the spin one Klein Gordon Equation? What is the formula for the conserved current, i.e. the electric current density four-vector?

Homework Helper
I don't know what do you understand by the spin-one KG equation...
But the KG equation is just ##(\square - m^2)\phi=0##.
So I would say that the KG equation for spin-one is just $$(\square - m^2)A^\mu=0$$

Demystifier
So I would say that the KG equation for spin-one is just $$(\square - m^2)A^\mu=0$$