There are several question here that ask why unicode-math
documents have a different alignment of subscripts
(1, 2, 3).
But they all share two common points: They think this is bug, and they think it is related to XeLaTeX only.
However, the document
\documentclass{minimal}
\usepackage{unicode-math}
\begin{document}
$a_b$
\end{document}
renders identical in XeLaTeX und LuaLaTeX, today. Although I am not sure I like the change, I think this is intended and I'd like to have an more or less official answer to that.
Left side: Rendering of XeLaTeX/LuaLaTeX with the code from above.
Right side: Rendering without \usepackage{unicode-math}
.
As you can see, different fonts are being used. So I guess the difference is due to that.
Do you think the differing subscript position this is intended behavior? Is there any more or less official statement about that?
sub1
orsub2
according to the LuaTeX manual.\usepackage{unicode-math}
.