Inverted circumflex not as diacritic

Question

How do I typeset a caron or inverted circumflex as a character on its own in math-mode, rather than as a diacritic above another character? I need to do this because I want to use it as a superscript, like fˇ. This is when describing a pair of functions: f^ and fˇ.

Answer 1

Something like this?

\documentclass{article}
\usepackage{amsmath} % for \text macro
\begin{document}
$f\text{\v{}}$ $f\text{\^{}}$ $f\text{\u{}}$ $f\text{\={}}$  $f\text{\.{}}$ $f\text{\"{}}$
\end{document}

Answer 2

Adjust the amount of lowering (now 0.5ex) to suit your need.

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\newcommand\post@accent[2]{%
  \mbox{\fontsize{#2}{\z@}\selectfont\raisebox{-0.5ex}[\dimexpr\height-0.5ex][0pt]{$\m@th\,#1{}$}}%
}
\newcommand{\definepostaccent}[2]{%
  \newcommand{#1}{\mathchoice{}{}{\post@accent{#2}{\f@size}}{\post@accent{#2}{\sf@size}}}%
}
\makeatother

\definepostaccent{\pcheck}{\check}
\definepostaccent{\pbreve}{\breve}

\begin{document}
Standard size

$f^{\pcheck}>f^{\pcheck}_{T}$ 

$f^{\pbreve}<f^{\pbreve}_{T}$

Subscript

$X_{f^{\pcheck}-f^{\pbreve}_{x}}$
\end{document}

Explanation

After \definepostaccent{\pcheck}{\check}, the macro \pcheck is defined to do

\mathchoice{}{}{\post@accent{\check}{\f@size}}{\post@accent{\check}{\sf@size}}

This means that \pcheck must be used only in superscripts; it will print a box where

1. the suitable font size is set: \f@size in first level superscripts, \sf@size in second level superscripts, which correspond to the normal font size and the superscript font size;

2. The box contains a 0.5ex lowered box which is given its natural height (\height-0.5ex) and zero depth

3. The lowered box contains the math accent, slightly shifted right.

Using ^{\pcheck} guarantees that a subscript will be printed in its usual position.

Answer 3

May I suggest an alternative approach: Use $\vee$ and $\wedge$ as superscripts, like $f^\vee$ and $f^\wedge$.