I met a question when I tried to express a vector, where every element inside is a matrix. We know the notion usually works like this:

  • scalar: $a$
  • vector: $\boldsymbol{a}$
  • matrix: $\boldsymbol A$
  • vector (elements inside are vector): $\boldsymbol{A} = [\boldsymbol{a}_1, \boldsymbol{a} _2, \boldsymbol{a} _3]$

What if I want to express a vector (or tensor) where the elements are matrices, like the following:

  • vector (elements inside are vector): $? = [\boldsymbol{A}_1, \boldsymbol{A} _2, \boldsymbol{A} _3]$

Should I still use $\boldsymbol A$, Or is there a formal expression?


This question is about conventions, and it will differ from field to field. You should use the conventions of your field.

Otherwise, the standard ISO 80000-2 identifies notation for scalars, vectors, matrices, tensors, and more. Symbols for tensors are in sans-serif bold italic. The isomath package implements this in LaTeX.

  • $\begingroup$ Thank you so much for your answer, Arya! I checked the materials you mentioned, and it seems the symbols of matrix(2-15.1) and tensor(2-17.19) are the same: both are sans-serif bold italic with a capital case. Thanks again! $\endgroup$ – Nick Chen Jun 14 at 3:10
  • $\begingroup$ The matrix notation has serifs. The tensors don’t. $\endgroup$ – Arya McCarthy Jun 14 at 3:14
  • $\begingroup$ Sorry I didn't notice that difference! Thank you so much for pointing it out. Problem solved! $\endgroup$ – Nick Chen Jun 14 at 3:45
  • 2
    $\begingroup$ +1 for isomath, great little package $\endgroup$ – Firebug Jun 14 at 17:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.