Symbol for a "twisted product"?

Question

I am trying to make a symbol for a "twisted product". I've tried stackrel:

$A \mathbin{\stackrel{\sim}{\times}} B$

but the sim floats too high above the times, causing unpleasant line spacing. I've also tried widetilde

$A \mathbin{\widetilde{\times}} B$

but it has the same problem. Ideally I'd like the tilde to have the same width as the times and for the spacing between the two to be pretty tight.

Have a look at “How to look up a math symbol?” for ideas how you can easily find a particular symbol. — Matthew Leingang, Mar 03 '11 at 18:20

score 11 · Accepted Answer · answered Mar 03 '11 at 18:35

11

Detexify didn't help, so maybe you really have to do it yourself:

\newcommand\simtimes{\mathbin{%
    \stackrel{\sim}{\smash{\times}\rule{0pt}{0.9ex}}%
    }}

Adjust the 0.9ex to your needs.

answered Mar 03 '11 at 18:35

Hendrik Vogt

37,935

1

Perfect. I used 0.6ex. Thank you very much! – Sam Nead Mar 03 '11 at 19:03

score 4 · Answer 2 · answered Mar 21 '19 at 23:54

The parameters 0.7 and 0.3 might be needed adjustment if used with different fonts.

\documentclass{article}
\usepackage{amsmath}
\usepackage{graphicx}

% a general purpose macro
\newcommand{\xmathpalette}[2]{\mathchoice
  {#1\displaystyle\textfont{#2}}%
  {#1\textstyle\textfont{#2}}%
  {#1\scriptstyle\scriptfont{#2}}%
  {#1\scriptscriptstyle\scriptscriptfont{#2}}%
}

\makeatletter
\newcommand{\twistedproduct}{%
  \mathbin{\xmathpalette\twisted@product\relax}%
}

\newcommand{\twisted@product}[3]{%
  \vbox{%
    \ialign{\hfil##\hfil\cr
      \scalebox{0.7}{$\m@th#1\sim$}\cr
      \noalign{\nointerlineskip\kern-0.3\fontdimen5 #2 2}
      $\m@th#1\times$\cr
    }%
  }%
}
\makeatother

\begin{document}

$S^2\twistedproduct S^2$ $X_{\twistedproduct_{\twistedproduct}}$

\end{document}

The macro \xmathpalette is an extension of \mathpalette that makes also the font in the current style (\textfont, \scriptfont or \scriptscriptfont). In this case we use it to access the x-height of the symbol font for the current style.

score 2 · Answer 3 · answered Dec 28 '17 at 04:47

For slightly improved spacing displayed and inline, you can use \ooalign. The code is

\newcommand{\twprod}{\mathbin{%
    \ooalign{\raise1.15ex\hbox{$\scriptstyle\sim$}\cr\hidewidth$\times$\hidewidth\cr}%
    }}

If you will ever use the symbol in a subscript or superscript, \mathchoice allows for greatly improved spacing in scriptstyle. The height of the \sim is easily adjustable by changing the 1.15ex for display and inline, .85ex for script and (though I can't imagine using it) .65ex for scriptscript.

\documentclass{article}

\newcommand{\twprod}{\mathbin{\mathchoice%
    {\ooalign{\raise1.15ex\hbox{$\scriptstyle\sim$}\cr\hidewidth$\times$\hidewidth\cr}}%
    {\ooalign{\raise1.15ex\hbox{$\scriptstyle\sim$}\cr\hidewidth$\times$\hidewidth\cr}}%
    {\ooalign{\raise.85ex\hbox{$\scriptscriptstyle\sim$}\cr\hidewidth$\scriptstyle\times$\hidewidth\cr}}%
    {\ooalign{\raise.65ex\hbox{$\scriptscriptstyle\sim$}\cr\hidewidth$\scriptscriptstyle\times$\hidewidth\cr}}%   
    }}

\begin{document}

$S^2\twprod S^2\quad F_{S^2\twprod S^2}$

\end{document}

score 2 · Answer 4 · answered Mar 22 '19 at 00:10

As shown, \ttimes has the same spacing as \times. It adjusts automatically to the math style.

\documentclass{article}
\usepackage{stackengine,scalerel}
\newcommand\ttimes{\mathbin{\ThisStyle{\ensurestackMath{%
  \stackengine{-1\LMpt}{\SavedStyle\times}
  {\SavedStyle_{\hstretch{.9}{\mkern1mu\sim}}}{O}{c}{F}{T}{S}}}}}
\begin{document}
$ A\ttimes C$\par
$ A\times C$\par
$ \scriptstyle A\ttimes C$\par
$ \scriptstyle A\times C$\par
$ \scriptscriptstyle A\ttimes C$\par
$ \scriptscriptstyle A\times C$\par
\end{document}

Symbol for a "twisted product"?

4 Answers4

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