```\mathcal``` and ```mathscr``` look the same in my template

Question

In my current template compiled by pdflatex, I am seeing \mathcal forced to \mathscr. For example, $\mathcal{T},\mathscr{T}$ leads to the output. Can anyone propose potential causes of this problem? P.S., this is what I believe to be a normal output from \mathcal{T}:

Answer 1

There is no “normal” \mathcal. Different font sets make different choices about it.

You should be aware that mathptmx is essentially a kludge. The text font is (a variety of) Times, the symbols are drawn from here and there with the main purpose of making documents as small and possible when translated to Postscript or, in more recent years, to PDF.

It happens that mathptmx uses the RSFS font also loaded by \usepackage{mathrsfs} for its \mathcal alphabet.

There are better alternatives to mathptmx nowadays.

mathptmx

\documentclass{article}
\usepackage{amsmath}
\usepackage{mathptmx}
\usepackage{mathrsfs}
\begin{document}
Some text $A\cap B\in\mathscr{P}(X)\ne\mathcal{P}(X)$ and some text
\end{document}

mathptmx with cmsy

\documentclass{article}
\usepackage{amsmath}
\usepackage{mathptmx}
\usepackage{mathrsfs}
\DeclareMathAlphabet{\mathcal}{OMS}{cmsy}{m}{n}
\begin{document}
Some text $A\cap B\in\mathscr{P}(X)\ne\mathcal{P}(X)$ and some text
\end{document}

newtxtext,newtxmath

\documentclass{article}
\usepackage{amsmath}
\usepackage{newtxtext,newtxmath}
\begin{document}
Some text $A\cap B\in\mathscr{P}(X)\ne\mathcal{P}(X)$ and some text
\end{document}

stix2

\documentclass{article}
\usepackage{amsmath}
\usepackage{stix2}
\usepackage{mathrsfs}
\begin{document}
Some text $A\cap B\in\mathscr{P}(X)\ne\mathcal{P}(X)$ and some text
\end{document}