Recent content by m_prakash02

I understand that adding gradient of a scalar to the electromagnetic field potential keeps the evolution equation of the four potential invariant. But how does that give us the freedom to choose the gauge?

Thanks for the reply! Could you please suggest me some resources for further reading?

I am a graduate physics student currently studying electrodynamics as a core paper. I want to know why exactly do we use only covariant formulation for writing Maxwell's equations? Or do we also use contravariant formulation (i.e., if something like that even exists)?