Hello all, long time lurker, first time poster. I don't know if I am posting this in the proper section, but I would like to ask the following:(adsbygoogle = window.adsbygoogle || []).push({});

In index notation the term [itex]σ_{ik}x_{j}n_{k}[/itex] is [itex]\bf{σx}\cdot\bf{n}[/itex] or [itex]\bf{xσ}\cdot\bf{n}[/itex], where ##σ## is a second order tensor and ##x,n## are vectors.

On the same note, is ##\frac{\partialσ_{ik}}{\partial x_{k}}x_{j}## equivalent to ##\nabla\cdot(\bf{xσ})## or ##\nabla\cdot(\bf{σx})## ? For some reason there is an index notation rule that eludes me.

Pardon me for the fundamendality or even stupidity of my questions!

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# Simple(?) index notation

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