Definition:Permutation Symbol
From ProofWiki
Definition
The permutation symbol $\varepsilon$ of a permutation $P$ of a set of elements is defined as $+1$ for even permutations (permutations that are an even number of pair swaps), $-1$ for odd permutations, and $0$ if the list of elements is not a permutation (i.e. contains a repeated value).
Frequently, the permutation will be explicit, eg, written
- $\varepsilon_{ijk\dots}$
- $\varepsilon^{ij\dots}_{kl\dots}$
- $\varepsilon^{ijk\dots}$
This notation is especially useful when raising and lowering indices (ie, converting between forms and vectors).