[Tex/LaTex] Central superscripts on \bigcup

Question

The \bigcup symbol allows you to write an upper bound (\bigcup_{lb}^{ub}) that will be centered on the top of the cup.
For my problem I'm defining a modified version of the union operator that I'd like to indicate ad \widetilde{\bigcup}, but I couldn't obtain the tilde between the cup and the upper bound

\widetilde {\bigcup_{\gamma = 1}^{n}} : puts the tilde above the n

\widetilde {\bigcup}_{\gamma = 1}^{n} : the upper bound is not centered

Any suggestion ?

Answer 1

This is the easiest way:

\documentclass{article}
\usepackage{amsmath}

\newcommand{\wbigcup}{\mathop{\widetilde{\bigcup}}\displaylimits}

\begin{document}
\[
\wbigcup_{i=1}^n A_i
\]
\end{document}

Note that \displaylimits is not really needed, but clarity is important.