Can you help add this font to my math font list?

Question

I found a PhD thesis using a math font I did not know yet:

I know these: \mathbb{}, \mathcal{}, \mathfrak{}, \mathscr{}, \mathsf{}, \EuScript{}, but none of these match the symbols above. Help me expand my library of symbols I can use!! :D

EDIT: Now I want to know how to make a new command in this font, without 'overwriting' the above commands. For example if I use \mathcalpxtx{XUY}, I will end up with the XUY in the image above. I tried to do this with this question, but I actually don't understand how this declare operator works...

Answer 1

This seems to be the calligraphic font often used with Times or Palatino clones. You can set \mathcal to this font with the option cal=pxtx from mathalpha, as in the following example.

\documentclass{article}
\usepackage[cal=pxtx]{mathalpha}
\begin{document}
\(\mathcal{XUY}\)
\end{document}

If you want to keep using the default calligraphic font as well, you can define the new alphabet without loading mathalpha and associate it with another command than \mathcal. To define the new alphabet, you can take the relevant lines directly from mathalpha's code.

\documentclass{article}
\DeclareFontFamily{U}{txcal}{\skewchar \font =45}
\DeclareFontShape{U}{txcal}{m}{n}{<-> txr-cal}{}
\DeclareMathAlphabet{\mathcalpxtx}{U}{txcal}{m}{n}
\begin{document}
\(\mathcal{XUY}\mathcalpxtx{XUY}\)
\end{document}