Why Does Index Position in Kronecker Delta and Tensors Not Always Matter?

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Homework Statement


kroenecker delta has one upper and one lower index. except from uppper index and lower index,we have 2 slots for the upper index and 2 slots for the lower index(for a 2 index tensor).
Why krenecker delta left or right slot index position doesn't matters?
Also why 2 two index tensors may not be equal because of the peculiarity of left and right slot index position?


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helpcometk said:
Why krenecker delta left or right slot index position doesn't matters?

That's just because of the definition. Tensors that behave like this are called symmetric.

helpcometk said:
Also why 2 two index tensors may not be equal because of the peculiarity of left and right slot index position?

I don't understand what this question means.
 
Because of the general definition of a tensor as a multilinear mapping, the order in which the vector spaces and their duals are chosen really matters, especially when the bundle of tensors is defined for a metric manifold (as is the case in relativity).

You will study electrodynamics and discover that the mixed components of the field tensor are all different, that is

F_{\mu}^{~~\nu} \neq F^{\nu}_{~~\mu}

for arbitrary index values.
 
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