I am writing some mathematics in which I want to use both typographic variants of the lowercase 'g' in math mode. See the Wikipedia page to see the two variants. There is a single-story and a double-story. I want to use the single-story to denote functions and the double-story to denote metrics on manifolds. Sometimes I want them in bold as well. Since I want them in math mode, bold or not they should be italicized. I can't find any commands like there are to access variants of Greek letters.
More generally I would like to know if there is a general way to access variants in plain text or in math mode, and not just in Computer Modern, because I want to end up typesetting my document with the font Times New Roman or something very similar (I am trying to match the typography in my document to the typography in the book Semi-Riemannian Geometry With Applications to Relativity by Barrett O'Neill.) Right now I am using the package
I know already that in Computer Modern, for instance, since the default text 'g' is the double-story and the default math 'g' is the single-story, I could get a double-story 'g' into an equation using
\mathrm, but it's not in italics so it looks strange. There must be a better solution.