I hope you could help me clearing some doubts about Gauss' law of the electric field that states ϵ0∇⋅→E=ρ. Take for instance the case of a point charge in the origin in empty space. The law states ∇⋅→E=0 anywhere but the origin, but it's enough to compute ∇⋅→E to get to a contradiction: →E=ξ[x,y]√(x2+y2)3 where I dropped every constant to ξ because that's my favourite greek letter, and considered the 2D case since in my opinion it's a good compromise between complexity and meaningfulness ∇⋅→E=−x2+y2√(x2+y2)5=(x2+y2)1−52 which is clearly not zero except at infinity.
Answer
As pointed out in the comment, Gauss' law has a precise geometric meaning and so is strongly dependent on the dimension of the space. Let's work in 2D as in your example and apply Gauss' law: the flux of the electric field through a circle centered in the point charge is 2πrE. This must be equal to the total charge which is e/ϵ0. This gives for the modulus of the electric field: E=e2πϵ0r and for the cartesian components: →E=e2πϵ0(xx2+y2,yx2+y2) As you can verify the divergence of this is zero: ∇⋅→E∝1x2+y2−2x2(x2+y2)2+1x2+y2−2y2(x2+y2)2=0
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