4

I'm experiencing a small glitch with index positions, because of the \dag (or \dagger) symbol. Here's a MWE showing the small issue:

\documentclass[11pt,letterpaper,twoside]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[nomath]{lmodern}
\usepackage[total={6in,10in},left=1.5in,top=0.5in,includehead,includefoot]{geometry}
\usepackage{microtype}
\usepackage{nccmath,amsmath}
\usepackage{amsfonts}
\usepackage{mathtools}
\usepackage{tensor}

\begin{document}

Blabla
\begin{equation}
    \psi^{\dag} \, \psi_{\text{L}}^{\dag} \, \tensor{\psi}{_{\text{L}}} = -\: \psi_{\text{R}}^{\dag} \, \tensor{\psi}{_{\text{R}}} \,  \, \psi_{\text{R}}.
\end{equation}

\end{document}

Here's a preview showing the vertical spacing problem:

enter image description here

As you can see, the subscripts doesn't have the same vertical position everywhere. I hate that! Smashing any of the symbols (subscript or the dag symbol) isn't a good solution since it would produce some overlapping, or the symbols would touch (which is uglier!).

The problem is clearly the dag symbol, which is pretty long. So is there a shorter dag symbol in LaTeX to replace the default one? I searched and found none.

Take note that the tensor package gives the right position for subscripts (it's more consistent). Removing the tensor "notation" would make the problem worst!

Maybe the best solution is to rise a bit the superscript symbol. How can I do that to the \dag symbol (i.e rise it a bit)?

6

Here, \Dag is made (by way of scaling) to take on the vertical footprint of a capital X.

Works across math styles.

See ADDENDUM for yet another alternative.

\documentclass[11pt,letterpaper,twoside]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[nomath]{lmodern}
\usepackage[total={6in,10in},left=1.5in,top=0.5in,includehead,includefoot]{geometry}
\usepackage{microtype}
\usepackage{nccmath,amsmath}
\usepackage{amsfonts}
\usepackage{mathtools}
\usepackage{tensor}
\usepackage{scalerel}
\newcommand\Dag{\scalerel*{\dag}{X}}
\begin{document}

Blabla
\begin{equation}
    \psi^{\Dag} \, \psi_{\text{L}}^{\Dag} \, \tensor{\psi}{_{\text{L}}} = -\: \psi_{\text{R}}^{\Dag} \, \tensor{\psi}{_{\text{R}}} \,  \, \psi_{\text{R}}.
\end{equation}
\begin{equation}
  \scriptstyle
    \psi^{\Dag} \, \psi_{\text{L}}^{\Dag} \, \tensor{\psi}{_{\text{L}}} = -\: \psi_{\text{R}}^{\Dag} \, \tensor{\psi}{_{\text{R}}} \,  \, \psi_{\text{R}}.
\end{equation}

\end{document}

enter image description here

One variation would be to replace, in the definition of \Dag, the \scalerel* with \stretchrel*. This would change the vertical dimension of \dag only, while preserving the original horizontal dimension:

enter image description here

For comparison, here is the original \dag, followed by the scaled \dag and the stretched \dag.

enter image description here

ADDENDUM

After comments back and forth, the OP requested a version that shifts the normally-sized \dag upward, and uses no extra packages. I created a version with \raisebox and \mathchoice, while using a trick (manually setting the depth of the particular \dag) to still keep it a little below the baseline:

\documentclass[11pt,letterpaper,twoside]{book}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[nomath]{lmodern}
\usepackage[total={6in,10in},left=1.5in,top=0.5in,includehead,includefoot]{geometry}
\usepackage{microtype}
\usepackage{nccmath,amsmath}
\usepackage{amsfonts}
\usepackage{mathtools}
\usepackage{tensor}
\usepackage{scalerel}
\newcommand\Dag{\mathchoice
  {\setbox0=\hbox{$\dag$}\dp0=.5\dp0\raisebox{\dp0}{\copy0}}
  {\setbox0=\hbox{$\dag$}\dp0=.5\dp0\raisebox{\dp0}{\copy0}}
  {\setbox0=\hbox{$\scriptstyle\dag$}\dp0=.5\dp0\raisebox{\dp0}{\copy0}}
  {\setbox0=\hbox{$\scriptscriptstyle\dag$}\dp0=.5\dp0\raisebox{\dp0}{\copy0}}
}
\begin{document}

Blabla
\begin{equation}
    \psi^{\Dag} \, \psi_{\text{L}}^{\Dag} \, \tensor{\psi}{_{\text{L}}} = -\: \psi_{\text{R}}^{\Dag} \, \tensor{\psi}{_{\text{R}}} \,  \, \psi_{\text{R}}.
\end{equation}
\begin{equation}
  \scriptstyle
    \psi^{\Dag} \, \psi_{\text{L}}^{\Dag} \, \tensor{\psi}{_{\text{L}}} = -\: \psi_{\text{R}}^{\Dag} \, \tensor{\psi}{_{\text{R}}} \,  \, \psi_{\text{R}}.
\end{equation}

\end{document}

enter image description here

  • What is the meaning of the X on \newcommand\Dag{\scalerel*{\dag}{X}}? Thank you! – manooooh Jan 15 at 0:54
  • 3
    @manooooh X is the glyph the rescaled dagger inherits the dimensions of. – Schrödinger's cat Jan 15 at 1:46
  • The second version appears better. Is it possible to simply truncate the symbol (at the bottom), instead of stretching or compressing it? – Cham Jan 15 at 14:11
  • 1
    @Cham Try: \usepackage{scalerel,stackengine} \newcommand\Dag{\ThisStyle{\abovebaseline[0pt]{$\SavedStyle\dag$}}} – Steven B. Segletes Jan 15 at 15:00
  • 1
    @Cham Here is a version without additional packages: \newcommand\Dag{\mathchoice {\setbox0=\hbox{$\dag$}\raisebox{\dp0}{\copy0}} {\setbox0=\hbox{$\dag$}\raisebox{\dp0}{\copy0}} {\setbox0=\hbox{$\scriptstyle\dag$}\raisebox{\dp0}{\copy0}} {\setbox0=\hbox{$\scriptscriptstyle\dag$}\raisebox{\dp0}{\copy0}} } – Steven B. Segletes Jan 15 at 15:13

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