I would like to use parenthesis that look like arrows:
Is there some way to get them that is simpler than drawing them in Tikz?
The alternative I see is taking some > symbol, rotating it and placing it properly, but this looks like the kind of thing that could break if the setting changes (i.e. the font changes, or we move from text mode to math mode, ...)
\usepackage{MnSymbol}
$\rcurvearrowdown \lcurvearrowdown$
works for you?