- #1

olgerm

Gold Member

- 533

- 34

is it true that##\frac{\partial f}{\partial x_\mu}=\frac{\partial f}{\partial x^\mu}*g_{\mu \mu}##?

how to lower some of indices if same indice is many times in same tensor or multipication? for example:

##T^{i_1 i_1 i_2}## to ##T_{i_1 i_1 i_2}##

##a^{\alpha}*b^{\alpha}*c^{\alpha}## to ##a_{\alpha}*b_{\alpha}*c_{\alpha}##?

how to lower some of indices if same indice is many times in same tensor or multipication? for example:

##T^{i_1 i_1 i_2}## to ##T_{i_1 i_1 i_2}##

##a^{\alpha}*b^{\alpha}*c^{\alpha}## to ##a_{\alpha}*b_{\alpha}*c_{\alpha}##?

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