# Tensors index notation

1. Sep 9, 2009

### vortmax

1. The problem statement, all variables and given/known data

Prove the following relationship:

$$\epsilon$$pqi$$\epsilon$$pqj = 2$$\delta$$ij

2. Relevant equations

3. The attempt at a solution

All I have so far is the decomposition using the epsilon-delta

$$\epsilon$$pqi$$\epsilon$$pqj = $$\epsilon$$qip$$\epsilon$$pqj
$$\epsilon$$qip$$\epsilon$$pqj = $$\delta$$qp$$\delta$$iq - $$\delta$$qj$$\delta$$iq

have no idea where to turn next

2. Sep 10, 2009

### lanedance

Hi vortmax, do you have a definition for the eijk (levi cevita) and understand the summation?

You could do it reasonably simply just by evaluating ij cases for both the levi cevitas & kronecka deltas (probably all you really need to do is i=j & i<>j cases)