# adding co-authors to customised title page for beamer presentation

I have customised my title page, using \title \date and \institute. I would like to add another line with co-authors, but I couldn't find any examples of how to do it. My ideas at the moment are

1. I could hi-jack \insertshortinstitute, since I don't use this in anywhere else.
2. I could define a new variable e.g. \def\mycoauthor{} (like on Use the values of \title, \author and \date on a custom title page) but then I don't know how to access it, especially since my maketitle definite is in a separate style file.

Here is a MWE showing how I create the title page at the moment, and an attempt to include coauthors:

\documentclass{beamer}
\usetheme{_MWE}

\title[short title]{TITLE TITLE TITLE TITLE TITLE TITLE}
\author[me]{A. U. Thor}
\def\coauthors{A. N. Other, J. Bloggs, J. Doe}
\institute[\coauthors]{My Institute}
\date{1.1.2012}

\begin{document}
\maketitle
\end{document}


beamertheme_MWE.sty:

\ProvidesPackage{beamertheme_MWE}

\makeatletter
\def\maketitle{%
\begin{frame}[plain]
{%
\vspace{10mm}
\parbox{122mm}%
{%
\centering
{\Large \inserttitle}\\
\vspace{8mm}
{\large \insertauthor}\\
\vspace{3mm}
{\large \insertshortinstitute}
\vspace{7mm}
{\small \insertinstitute}\\
\vspace{-5mm}
{\flushleft
\hspace{1mm}
LOGO1
\hspace{60mm}
\raisebox{0.5mm}{
LOGO2
\hspace{10mm}
}
}\\
\vspace{0mm}
{
\parbox{53mm}{\centering \small \insertdate\\
}
}
}
}
\end{frame}
}
\makeatother


incidentally... why doesn't the \centering command work for \insertshortinstitute, and why do I get an error "there's no line here to end" if I put a \\ after it, as I do with \author etc.?

-
I should add that I don't want to use the \thanks construct, since I don't think superscripts are the right way to refer to co-authors... unless someone knows a way to use \thanks and get the formatting I want? –  craq Oct 31 '12 at 13:19

I think \author uses a minipage internally, so you can use something like

\author[me]{A. U. Thor\\[3mm]A. N. Other, J. Bloggs, J. Doe}


and forget \coauthors except you want to use them somewhere else.

If you use this construction, delete \insertshortinstitue form your style.

-
thanks, that gives me what I want. I forgot to mention before, but I also wanted to change the font size. That works the same way, so what I've got now is: code \def\coauthors{A. N. Other, J. Bloggs, J. Doe} \author[me]{A. U. Thor\[3mm]\small \coauthors} \institute[my institute]{My Institute} code (and of course I removed the line with \insertshortinstitute in the style file) –  craq Oct 31 '12 at 16:24
I have a follow-up question: when I moved this solution from my MWE back to my real presentation, the new author line conflicts with another package in my style file: \usepackage[utf8x]{inputenc}. Other options to inputenc (ansinew, latin1 and latin9) compile with no problems. The error message I get is: ! Missing } inserted. <inserted text> } l.6 ...3mm] \small A. N. Other, J. Bloggs, J. Doe} [etc....etc....etc...] ! LaTeX Error: Missing \begin{document}. Do you know what's going on here, or how to get around it? –  craq Oct 31 '12 at 17:13
added as separate question: tex.stackexchange.com/questions/81641/… –  craq Nov 6 '12 at 12:49