Conditions for a E field to be possible

1. Nov 23, 2013

cutesteph

If I want to verify an electric field E is possible in free space, do I just need to check ∇xE =0?

2. Nov 23, 2013

WannabeNewton

In free space what always has to hold is $\vec{\nabla}\cdot \vec{E} = 0$ whereas $\vec{\nabla}\times \vec{E} = 0$ only holds in electrostatic systems. Is your system electrostatic?

3. Nov 23, 2013

cutesteph

Yes, the system is electrostatic.

4. Nov 23, 2013

WannabeNewton

Then yes you have to check that the electric field is irrotational. You also have to check that it is divergence-free.