How to change the text font in a document to "Times" and keep the font for equations unchanged (i.e Computer Modern)?
One thing I like to do, which might be related to what you want, is to put this in my header:
It changes all my body text to Times, but is not the same as
because it doesn't change the typewriter font to Courier, and it doesn't change the sans-serif font to Helvetica; it leaves both of those as the standard Computer Modern versions.
This is the XeLaTeX version using
In General, the current font depends on some parameters such as 'size', 'family', 'series', and 'shape'. For example, if one says
But before LaTeX changes the current font, LaTeX need to know the exact font family you want. (Since 'sans serif' is not really a font family but more like 'description' about fonts.) This information is stored in
Therefore editing it by
The bad news is that font packages for body texts sometimes change the math font simultaneously. This makes your document looks more compatible. So
under this answer Mico mentioned another bad news: Some fonts are named different on different system. For example