# Help with Indicial Notation!

1. May 1, 2013

### muzialis

Hi there,

I am trying to get some practice with indicial notation.
Given a vectorial function $$v_j = a_j e^{i(k_k x_k - \omega t)}$$ of spatial variables $$x_i$$ and time, given a tensor $$K_{ijkl}$$ I want to compute the quantity
$$K_{2jkl} v_{k,l}$$.
I get $$K_{2jkl} a_l i k_k e^{i(k_m x_m - \omega t)}$$, while the correct result is
$$K_{2jkl} k_k a_ l e^{i(k_m x_m - \omega t)}$$.

Can anybody help?

Thanks

2. May 1, 2013

### Fredrik

Staff Emeritus