# Delta-like symbol in LaTeX

I'd like to write a majuscule delta-like symbol in LaTeX but I can't find it's syntax anywhere. You can see the symbol on equation (12) of the following paper:

"Two-Frame Motion Estimation Based on Polynomial Expansion".

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## migrated from stackoverflow.comMay 23 '11 at 16:44

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From your description, it seems you mean \triangle, \Delta or \vartriangle.

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That is a very cool site! But I still can't find the symbol. It is more like a majuscule delta in italic. Please check equation 10 on the paper to see what I'm talking about. –  Renan May 23 '11 at 2:39

That is just $\Delta$ which is different from $\delta$. LateX symbols are case-sensitive. See any of the LaTeX cheat sheets as e.g. this one a U Colorado.

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Thanks for the cheat sheet, but it is not a regular delta. Is as if it was in italic. Please check the paper to see what I'm talking about. –  Renan May 23 '11 at 2:37
Same symbol, different font. –  Dirk Eddelbuettel May 23 '11 at 2:50
@Renan: What if you typeset it in italics, e.g. \mathit{\Delta}? –  Torbjørn T. May 23 '11 at 17:01

Note that the document uses Springer's LNCS style. In this style, all Greek letters are in italics, and vectors are denoted by boldface.

Most likely the bold italic Delta is produced in this particular case by something similar to this:

\documentclass{llncs}
\begin{document}
$\vec{\Delta}$
\end{document}


The result is:

Note that if you used the article class, the same code would produce a normal Delta with an arrow:

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If one really wants a bold italic Delta, the way to go is

\usepackage{bm}
\newcommand{\bfitDelta}{\bm{\mathit{\Delta}}}


Of course, one could write every time \bm{\mathit{\Delta}}.

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