How to write upper case \varepsilon in LaTeX math environment?

Question

I need the uppercase of this sign $\varepsilon$ how to I get that?

related: http://tex.stackexchange.com/questions/111544/what-is-the-capital-greek-letter-for-tau/111548#111548 — Count Zero, Jul 01 '13 at 19:51
to be more specific this is the letter I am looking for link @egreg — Kristof Tak, Jul 01 '13 at 21:14

score 66 · Accepted Answer · answered Jan 07 '14 at 08:16

66

Found the answer here:

It turns out, it's not an epsilon, but a curved letter "E". To enter it in LaTeX, simply do \mathcal{E}.

answered Jan 07 '14 at 08:16

buzjwa

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Thanks, this should be the accepted answer because you don't have to jump through hoops. – DerManu Jul 03 '15 at 16:54

score 11 · Answer 2 · edited Jun 12 '17 at 17:17

There is a Unicode symbol U+2107 "Euler Constant" that at least looks like an uppercase variant of \varepsilon. The following example shows the symbol for different Unicode math fonts for users of XeLaTeX or LuaLaTeX:

\documentclass{article}

\usepackage{unicode-math}
\setmathfont{latinmodern-math.otf}
%\setmathfont{Asana-Math.otf}
%\setmathfont{xits-math.otf}

\begin{document}

\newcommand*{\cs}[1]{%
  \texttt{\textbackslash#1}%
}
\newcommand*{\test}[1]{%
  {\setmathfont{#1}$\varepsilon$} &
  {\setmathfont{#1}$\Eulerconst$}% 
}
\begin{tabular}{lll}
Macro name: & \cs{varepsilon} & \cs{Eulerconst} \\
Unicode code point: & U+03F5 & U+2107 \\
\hline
Latin Modern Math: & \test{latinmodern-math.otf} \\
Asana Math: & \test{Asana-Math.otf} \\
XITS Math: & \test{xits-math.otf} \\  
\end{tabular}

\end{document}

This is clearly a math symbol, but it's has a name indicating a very specific meaning. So should one use u+2107 or rather u+0190 in math cases, where the Euler constant is not meant? — Toscho, Jul 01 '13 at 22:42

score 3 · Answer 3 · edited Apr 13 '17 at 12:35

The letter is available in the T4 encoding for African languages, which is not very widespread: in the standard TeX distributions, only the CMR family is supported.

On the other hand, several OpenType or TrueType fonts have the glyph, precisely U+0190 LATIN CAPITAL LETTER OPEN E, rendered Ɛ.

So it depends on your setting. If you use pdflatex and Computer Modern fonts, a variant of this answer allows to define a glyph that changes size in subscripts/superscripts:

\documentclass{article}
\usepackage[T4,T1]{fontenc}
\makeatletter
\newcommand{\do@openE}[1]{%
  \mbox{\fontsize{#1}\z@\usefont{T4}{cmr}{m}{n}\symbol{130}}%
}
\newcommand{\openE}{\mathord{\mathchoice
  {\do@openE\tf@size}
  {\do@openE\tf@size}
  {\do@openE\sf@size}
  {\do@openE\ssf@size}
}}
\makeatother

\begin{document}
$E\ne\openE_{E\ne\openE}$
\end{document}

enter image description here

However the T4 encoded font is only available as bitmap and you might need to increase the default resolution (which is 600dpi) and creation mode for METAFONT.

If you're in a XeLaTeX/LuaLaTeX setting, then any font that has the glyph can be used, here CMU Serif (similar to the default Latin Modern)

\documentclass{article}
\usepackage{unicode-math}
\newfontfamily{\cmuserif}{CMU Serif}

\makeatletter
\newcommand{\do@openE}[1]{%
  \mbox{\fontsize{#1}\z@\cmuserif\symbol{"0190}}%
}
\newcommand{\openE}{\mathord{\mathchoice
  {\do@openE\tf@size}
  {\do@openE\tf@size}
  {\do@openE\sf@size}
  {\do@openE\ssf@size}
}}
\makeatother

\begin{document}
$E\ne\openE_{E\ne\openE}$
\end{document}

enter image description here

How to write upper case \varepsilon in LaTeX math environment?

3 Answers3