ctexbeamer + sjtubeamer 无法显示 \mathbf{\Psi}

[LogCreative]

粗体大写希腊字母在 ctexbeamer + sjtubeamer 下会消失：

\documentclass{ctexbeamer}
\usetheme{sjtubeamer}
\begin{document}
\begin{frame}
    $\mathbf{\Gamma} \mathbf{\Delta} \mathbf{\Theta} \mathbf{\Lambda}
    \mathbf{\Xi} \mathbf{\Pi} \mathbf{\Sigma} \mathbf{\Upsilon}
    \mathbf{\Phi} \mathbf{\Psi} \mathbf{\Omega}$
\end{frame}
\end{document}

而如果只使用 beamer 文档类时不会。

[LogCreative]

最简单的做法是在 ctexbeamer 文档类加载时添加 no-math 选项。

- \documentclass{ctexbeamer}
+ \documentclass[no-math]{ctexbeamer}
\usetheme{sjtubeamer}
\begin{document}
\begin{frame}
    $\mathbf{\Gamma} \mathbf{\Delta} \mathbf{\Theta} \mathbf{\Lambda}
    \mathbf{\Xi} \mathbf{\Pi} \mathbf{\Sigma} \mathbf{\Upsilon}
    \mathbf{\Phi} \mathbf{\Psi} \mathbf{\Omega}$
\end{frame}
\end{document}

原因：目前 sjtubeamer 的 font theme 主要只加载了 beamer 的 professionalfonts 主题让数学字体仍然是原始的衬线体：

SJTUBeamer/beamerfontthemesjtubeamer.sty

Line 27 in 4cec95d

\usefonttheme{professionalfonts}

例子可以简化为

\documentclass{ctexbeamer}        % compared with \documentclass{beamer}
\usefonttheme{professionalfonts}
\begin{document}
\begin{frame}
    $\mathbf{\Gamma} \mathbf{\Delta} \mathbf{\Theta} \mathbf{\Lambda}
    \mathbf{\Xi} \mathbf{\Pi} \mathbf{\Sigma} \mathbf{\Upsilon}
    \mathbf{\Phi} \mathbf{\Psi} \mathbf{\Omega}$
\end{frame}
\end{document}

将与只使用 beamer 文档类进行比较，后者是可以显示的。

日志比较 `test.ctex.log` 与 `test.log`

812,871c629
< ) (/usr/local/texlive/2023/texmf-dist/tex/latex/ctex/dictionary/translator-theorem-dictionary-ChineseUTF8.dict
< Dictionary: translator-theorem-dictionary, Language: ChineseUTF8 2022/07/14 v2.5.10 Chinese translation for theorem name (CTEX)
< )
< 
< Package fontspec Info: Adjusting the maths setup (use [no-math] to avoid
< (fontspec)             this).
< 
< \symlegacymaths=\mathgroup6
< LaTeX Font Info:    Overwriting symbol font `legacymaths' in version `bold'
< (Font)                  OT1/cmr/m/n --> OT1/cmr/bx/n on input line 3.
< LaTeX Font Info:    Redeclaring math accent \acute on input line 3.
< LaTeX Font Info:    Redeclaring math accent \grave on input line 3.
< LaTeX Font Info:    Redeclaring math accent \ddot on input line 3.
< LaTeX Font Info:    Redeclaring math accent \tilde on input line 3.
< LaTeX Font Info:    Redeclaring math accent \bar on input line 3.
< LaTeX Font Info:    Redeclaring math accent \breve on input line 3.
< LaTeX Font Info:    Redeclaring math accent \check on input line 3.
< LaTeX Font Info:    Redeclaring math accent \hat on input line 3.
< LaTeX Font Info:    Redeclaring math accent \dot on input line 3.
< LaTeX Font Info:    Redeclaring math accent \mathring on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Gamma on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Delta on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Theta on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Lambda on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Xi on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Pi on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Sigma on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Upsilon on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Phi on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Psi on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \Omega on input line 3.
< LaTeX Font Info:    Redeclaring math symbol \mathdollar on input line 3.
< LaTeX Font Info:    Redeclaring symbol font `operators' on input line 3.
< LaTeX Font Info:    Encoding `OT1' has changed to `TU' for symbol font
< (Font)              `operators' in the math version `normal' on input line 3.
< LaTeX Font Info:    Overwriting symbol font `operators' in version `normal'
< (Font)                  OT1/cmr/m/n --> TU/lmr/m/n on input line 3.
< LaTeX Font Info:    Encoding `OT1' has changed to `TU' for symbol font
< (Font)              `operators' in the math version `bold' on input line 3.
< LaTeX Font Info:    Overwriting symbol font `operators' in version `bold'
< (Font)                  OT1/cmr/bx/n --> TU/lmr/m/n on input line 3.
< LaTeX Font Info:    Overwriting symbol font `operators' in version `normal'
< (Font)                  TU/lmr/m/n --> TU/lmr/m/n on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathit' in version `normal'
< (Font)                  OT1/cmr/m/it --> TU/lmr/m/it on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathbf' in version `normal'
< (Font)                  OT1/cmr/bx/n --> TU/lmr/b/n on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathsf' in version `normal'
< (Font)                  OT1/cmss/m/n --> TU/lmss/m/n on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathtt' in version `normal'
< (Font)                  OT1/cmtt/m/n --> TU/lmtt/m/n on input line 3.
< LaTeX Font Info:    Overwriting symbol font `operators' in version `bold'
< (Font)                  TU/lmr/m/n --> TU/lmr/b/n on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathit' in version `bold'
< (Font)                  OT1/cmr/bx/it --> TU/lmr/b/it on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathsf' in version `bold'
< (Font)                  OT1/cmss/bx/n --> TU/lmss/b/n on input line 3.
< LaTeX Font Info:    Overwriting math alphabet `\mathtt' in version `bold'
< (Font)                  OT1/cmtt/m/n --> TU/lmtt/b/n on input line 3.
<  (./test.nav)
---
> ) (./test.nav)
879,892c637
< )
< Missing character: There is no ^^@ (U+0000) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^A (U+0001) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^B (U+0002) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^C (U+0003) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^D (U+0004) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^E (U+0005) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^F (U+0006) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^G (U+0007) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^H (U+0008) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no ^^I (U+0009) in font [lmromandemi10-regular]:mapping=tex-text;!
< Missing character: There is no 
<  (U+000A) in font [lmromandemi10-regular]:mapping=tex-text;!
< [1
---
> ) [1

日志显示 ctex 会加载 fontspec 包，在没有使用 no-math 选项时会更改字体定义。也就意味着对于未添加 no-math 选项的 fontspec 情况都是这样的，也就意味着对于加载了 ctex （没有额外选项）的情况也是这样的。