9

When I write

\varphi^{-1}\left(\bigcap_{\substack{\mathfrak{p} < B \\ p \text{ prime}}} \mathfrak{p}\right)

I get something like this:

enter image description here

Apparently it's leaving symmetric amounts of room for the sub- and superscripts. How do I get rid of all that excess space at the top?

EDIT: It's not so clear from the closeup I posted, but here's an example of how ridiculous it looks in context:

enter image description here

Daniel McLaury
  • 587
  • You know that this will look awkward either way... if you push up the content, \bigcap will not be vertically centred on the math axis. Alternatively, shrinking the brackets without raising the internal content would make this look too low. – Werner Apr 14 '13 at 05:55
  • See the example in context above -- it would look a lot better if the brackets shrank just to wrap the actual ink, even if that made them asymmetric. I'm also not married to the idea of the \bigcap being vertically centered. – Daniel McLaury Apr 14 '13 at 05:58
  • It's not an actual answer, but how about moving the _p_ prime to the end of the equation? Something like .../right) \quad\forall\quad p\in\mathcal{P} where \mathcal{P} is the set of prime numbers of interest? – Holene Apr 14 '13 at 06:44
  • These are actually prime ideals in a ring. I guess I could write [\mathfrak{p}] \in \Spec B instead. – Daniel McLaury Apr 14 '13 at 08:30

2 Answers2

14

Use \Big or \bigg; my preference would go to the former. It's not necessary that the parentheses encompass the whole contents, they are just delimiters. Surely having them asymmetric with respect to the formula axis would be worse.

\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}
\[
\varphi^{-1}\left(\bigcap_{\substack{\mathfrak{p} < B \\ p \text{ prime}}} \mathfrak{p}\right)
\]
\[
\varphi^{-1}\Bigl(\bigcap_{\substack{\mathfrak{p} < B \\ p \text{ prime}}} \mathfrak{p}\Bigr)
\]
\[
\varphi^{-1}\biggl(\bigcap_{\substack{\mathfrak{p} < B \\ p \text{ prime}}} \mathfrak{p}\biggr)
\]
\end{document}

enter image description here

Compare with

\[
\varphi^{-1}
\mathopen{\raisebox{-1.8ex}{$\Biggl($}}\,
\bigcap_{\substack{\mathfrak{p} < B \\ p \text{ prime}}} \mathfrak{p}
\mathclose{\raisebox{-1.8ex}{$\Biggr)$}}
\]

where the parentheses have been shifted down

enter image description here

Halil Sen
  • 277
egreg
  • 1,121,712
7

you can raise it but that doesn't look nice:

\documentclass{article}
\usepackage{amssymb}
\usepackage{amsmath}
\begin{document}

\[
\varphi^{-1}
\left(\array{@{}c@{}}
  \displaystyle\bigcap\\
  \substack{\mathfrak{p} < B \\ p \text{ prime}}\endarray 
\mathfrak{p}\right)
\]

\end{document}

enter image description here

Moriambar
  • 11,466
  • That looks great to me, though in context I'd like to lower the bit in parens so that the \bigcup is centered (and the parens are not). Is there a way to do this? (I don't understand what your code does.) – Daniel McLaury Apr 14 '13 at 08:35
  • try \raisebox{-2ex}{$\displaystyle\bigcap$}\\ for that line –  Apr 14 '13 at 08:39