I'm struggling to understand some aspects of a very basic gauge, the coulomb gauge.
So I am asking simpler questions.
If $\nabla \cdot A = 0$ ?
So $\frac{\partial A_x}{\partial x} + \frac{\partial A_y}{\partial y} + \frac{\partial A_z}{\partial z} = 0 $
By Poincare's lemma, there should exist a G such that
$A = \nabla \times G$ (I think)
I believe there is a thing called the Helmholtz decomposition theorem that is supposed to help solve this, but to be honest, I would prefer to keep theorems and lemmas out of this.
Are these two facts enough to determine A? If so how does this proceed in the simplest possible way at a basic calculus level?