# Revtex - using math in footnote

How one can use mathematics in footnote using ReVteX? I have a particular problem with \rangle

Minimal Example:

\documentclass[aps,amsmath,amssymb, prl]{revtex4-1}

\begin{document}

TEST\footnote{footnote with math $\langle X \rangle$ }

\end{document}


-
Welcome to TeX.SE! – yo' Jan 22 '13 at 13:38
Congrats on this nice little, really minimal working example. We don't see such here too often by new users. – Benedikt Bauer Jan 22 '13 at 15:33
thnx! I was really in a puzzle, with the footnote.. – KrzysiekP Jan 23 '13 at 9:00

This happens only when the footnotes are inserted in the reference section. The problem is that \langle becomes written as \delimiter "426830A (and similarly for \rangle.

Those double quotes confuse the BibTeX parser.

There are a few strategies available:

1. Safest. Enclose the math into \unexpanded:

\footnote{footnote with math \unexpanded{$\langle X \rangle$}}

2. Safe. Use \protect before commands that can go after \left and \right

\footnote{footnote with math $\protect\langle X \protect\rangle$}

3. Hack. Enclose the math in braces.

-
Yes, now it is working. Thanks for all solutions!! – KrzysiekP Jan 23 '13 at 8:54

Often helps, and here as well:

• If something surprisingly doesn't work, put it into a box :-)

\footnote{footnote with math \mbox{$\langle X \rangle$}}


(Version: if line breaks don't work, use \parbox)

• If something with BibTeX doesn't work, try putting it into braces:

\footnote{footnote with math {$\langle X \rangle$}}


Both ways work here. Simple braces are preferable.

Note for readers who test: BibTeX is required for footnotes with REVTeX.

-
Even just putting the math inside curly braces does the job. (I.e., the \mbox can be omitted.) – John Collins Jan 22 '13 at 14:49
@JohnCollins very good remark, thanks! – Stefan Kottwitz Jan 22 '13 at 15:23