Using pandoc with
---
header-includes:
- \usepackage{bm}
---
and --pdf-engine=pdflatex test.md -o test.pdf:
(\beta is italic, but this is another question)
Now using --pdf-engine=xelatex, it gives more problems, I need to de-use package{bm} and the only thing that runs is:
but the \beta is not good bold .
So, I can either \usepackage{bm} with \bm{\beta} or \boldsymbol{\beta}. The later is more portable because xelatex will compile (although not giving the right bold beta).