# Omitting the following parentheses

      \documentclass{beamer}
\usepackage{pifont}
%\usepackage{etoolbox} (this is necessary for old beamer versions)
%\usepackage{graphicx}
%\usepackage{color}

\newtheorem{proposition}[theorem]{Proposition}
\definecolor{kaiscyan}{RGB}{0,139,139}

\BeforeBeginEnvironment{proposition}{%
\setbeamercolor{block title}{fg=white,bg=kaiscyan}
\setbeamercolor{block body}{fg=black, bg=kaiscyan!20!white}
}
\AfterEndEnvironment{proposition}{
\setbeamercolor{block title}{use=structure,fg=white,bg=structure.fg!75!black}
\setbeamercolor{block body}{parent=normal text,use=block title,bg=block title.bg!10!bg}
}

\begin{document}

\begin{frame}
\begin{proposition}[\hfill{[\ding{43} The authors (year)]}]
A proposition.
\end{proposition}
\end{frame}

\end{document}


I want to omit the following parentheses

You will have to change the relevant beamer template. If you are always using the hand there you can add it to the template:

\documentclass{beamer}
\usepackage{pifont}
%\usepackage{etoolbox} (this is necessary for old beamer versions)
%\usepackage{graphicx}
%\usepackage{color}

\makeatletter
\newtheorem{proposition}[theorem]{Proposition}
\definecolor{kaiscyan}{RGB}{0,139,139}

\BeforeBeginEnvironment{proposition}{%
\setbeamertemplate{theorem begin}
{%
\begin{\inserttheoremblockenv}
{%
\inserttheoremname
\inserttheoremnumber
\fi
}%
}%
\setbeamercolor{block title}{fg=white,bg=kaiscyan}%
\setbeamercolor{block body}{fg=black, bg=kaiscyan!20!white}%
}
\AfterEndEnvironment{proposition}{
\setbeamercolor{block title}{use=structure,fg=white,bg=structure.fg!75!black}
\setbeamercolor{block body}{parent=normal text,use=block title,bg=block title.bg!10!bg}
}

\begin{document}

\begin{frame}
\begin{proposition}[The authors (year)]
A proposition.
\end{proposition}

\begin{proposition}[another]
A proposition.
\end{proposition}

\begin{proposition}
A proposition.
\end{proposition}
\end{frame}

\end{document}


• Thank you however I will not use always the hand – Student Apr 20 at 15:53
• Then change \hfill[\ding{43} \inserttheoremaddition]% to \hfill \insertheoremaddition. Then your original input will work. – Ulrike Fischer Apr 20 at 15:55
• Thank you. Also please why the proposition are numbred? – Student Apr 20 at 15:57
• Because of the \inserttheoremnumber. If you don't want it remove it. – Ulrike Fischer Apr 20 at 15:57