Eddington permutation symbol "e"
 

I recently came across the mathematical term "Eddington permutation" when trying to use tensor analysis to make a 3D grid around a ship surface. Could someone tell me what it means? Thank you, rajesh

Re: Eddington permutation symbol "e"
 

I believe you are talking about the permutation symbol e\ijk, that often is used to symbolically represent the cross product in indexial notations as AxB=e\ijkA\jB\k. (Note that I'm using \i to represent lower index). Also, A and B are vectors. Here, e\123=e\231=e\312=1 (positive permutation of indexes), e\132=e\213=e\321=-1 (negative permutation), otherwise e\ijk=0 (i.e. if any repeating combination of indexes occur).

Also, note that e\ijk is NOT a tensor, as it does not satisfy the tensor transformartion rule. However, many people used to call it "tensor".

It is a very useful symbol to make your notes elegant and compact.

Re: Eddington permutation symbol "e"
 

Yep, and he is probably confusing "Eddington" with "Einstein". The eps_ijk is sometimes called "Einstein's permutation symbol". Antother name for it is "Levi-Civita Tensor Density"

Re: Eddington permutation symbol "e"
 

Thank you so much guys.