\vec{p_{\bar p}} renders strangely

Question

When I do:

\vec{p_{\bar p}}

I get:

strange rendering

instead of

proper-ish rendering

with the \vec shifted over a bit. Why does this happen?

(Also, \vec{\mbox{p_{\bar p}}} renders identically, even though \mbox{p_{\bar p}} looks fine, which clashes with my previous mental model of \mbox – I thought that things outside the box don't really affect things inside the box; guess I'm wrong.)

Sorry, I guess I wasn't quite clear. That's how I got my second image, but what if I want the \vec arrow to be shifted to the right to be centered over the entire p_p "block"? — Sophie Alpert, Mar 06 '12 at 18:13
(Also not suggesting that this would be the best way to typeset this, but I'm wondering why what I tried breaks.) — Sophie Alpert, Mar 06 '12 at 18:14

score 10 · Accepted Answer · edited Apr 13 '17 at 12:35

10

This seems connected to the bug already examined in the question Why do arguments to nested \tilde or \breve commands reappear when amsmath is used?

Indeed, if amsmath is not loaded, your code works fine.

The solution is to avoid nesting:

$\vec{p}_{\bar{p}}$

which is, in my opinion, more mathematically sound.

edited Apr 13 '17 at 12:35

Community

1

answered Mar 06 '12 at 18:16

egreg

1,121,712

Gotcha, thanks for the explanation (both here and on the other question)! – Sophie Alpert Mar 06 '12 at 19:20

\vec{p_{\bar p}} renders strangely

1 Answers1