Emphasize (make bold) texts within a subscript for LaTeX exports?

There are some mathematical equations in the form of:

G_{u}

which I enter in org-mode as

`\$G_{*u*}\$` or `\$G_{ *u* }\$`

It gets displayed correctly in org-mode, but when exported to LaTeX, the asterisks are interpreted as literal texts.

Is there a way to get LaTeX export to properly recognize that the subscript should be wrapped in `\textbf{}`?

There doesn't seem to be a problem with non-subscript texts, e.g. `\$ *X* \$`.

My understanding of the LaTeX exporter is that it recognizes raw LaTeX, and passes it unchanged to the LaTeX compiler. So you can use either org markup, or LaTeX markup, but you can't nest org markup inside LaTeX markup. eg:

No boldface, works as expected:
\$G_{u}\$

Nesting org markup inside a LaTeX element, doesn't work:
\$G_{*u*}\$

Using regular LaTeX without org markup:
\$G_{\textbf{u}}\$

Produces:

• Makes sense. The `\$\$` makes it part of LaTeX environment already. I should pay attention to that in the future. – xji Jun 13 '18 at 21:51