For the following document, I looked with a pdf viewer at the pdf metadata, and the author field is empty.

Can anyone tell me why?

```
% !TEX TS-program = lualatex
\pdfextension info {
/Title (pdf file title)
/Author (Foo)
/Subject (mathematics)
/Producer (LuaLaTex)
/Creator (LaTeX and Beamer)
/ModDate (D:20260418002300Z)
/CreationDate (D:20260417000000Z)
/Keywords (group theory, linear algebra)
}
\documentclass{beamer}
\title[]{My presentation}
\author[]{John Doe}
\begin{document}
\maketitle
\begin{frame}
Hello World
\end{frame}
\end{document}
```