tensors : several introductions

Tensors inevitably play a role in the world of hyperfine interactions. Quite some people struggle with this concept. If that applies to you, you may want to refresh your knowledge about tensors, or even finally trying to get it all straight.

Here are some resources that may help:

• Tensors as explained on Wikipedia: never bad as a start, although perhaps a bit condensed. The section ‘definition – as multidimensional arrays’ is useful.
• There is an old text on tensors that has been written for an early version of this course. It takes your hand and guides you to the places you need to have visited. It hasn’t been touched since years, and perhaps I would write it in a different way now, but it still can be helpful as an introduction.
• A free book by Ruslan Sharipov is by far the most clear and exciting introductory text about tensors I’m aware of. Thorough, engaging, and not too long. If you really want to understand the concept once and for ever, then this book (or the first sections of it) are very much recommended.

If you keep strugling with tensors and you meet specific troubles about them during this course, then don’t hesitate to ask your questions via the usual ways.