# Bug in Markdown editor with LaTex (array environment does not work)?

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in Q2A Core
edited

After installing the markdown editor with LaTex

writing math worked nicely, until I tried to use the

\begin{array}

\end{array}

environment , for example as in this question:

Looking at $5D$ Kaluza-Klein theory, the Kaluza-Klein metric is given by

$$g_{mn} = \left( \begin{array}{cc} g_{\mu\nu} & g_{\mu 5} \\ g_{5\nu} & g_{55} \\ \end{array} \right)$$

where $g_{\mu\nu}$ corresponds to the ordinary four dimensional metric and $g_{\mu 5}$ is the ordinary four dimensional Maxwell gauge field, $g_{55}$ is the dilaton  field.

As there is one dilaton for one extra dimension, I naively would expect that the zero mass states of closed string theory, which can be written as

$$\sum\limits_{I.J} R_{I.J} a_1^{I\dagger} \bar{a}_1^{I\dagger} ¦p^{+},\vec{p}_T \rangle$$

and the square matrix $R_{I.J}$ can be separated into a symmetric traceless part corresponding to the graviton field, an antisymmetric part corresponding to a generalized Maxwell gauge field, and the trace which corresponds to the dilaton field.

Why is there only one dilaton field given by the trace of $R_{I.J}$, instead of $22$ dilaton fields corresponding to $22$ extra dimensions of closed string theory which has critical dimension $D = 26$? For example, why are there not $22$ dilaton fields needed to parameterize the shape of the 22 extra dimensions if they are compactified?

Bug:

In the preview, all of the math compiles apart from the fact that the array is displayed as a single column instead of a 2x2 matrix.

When posting the question, all of the maths get scrampled up.

Howver, looking at the edit history by applying this plug-in

all the maths works including the matrix.

Is there the same problem with the \begin{bmatrix}\end{bmatrix} or the  \begin{pmatrix}\end{pmatrix} format ?
by
That does not work either ... :-/

+1 vote
I'm the author of this plugin and it's buggy I know... Sorry for that...

But, I have a good news ;)

Please move to q2a ckeditor latex plugin :  https://github.com/thibaultduponchelle/q2a-ckeditor-latex

This is not a markdown editor but a std wysiwyg ckeditor4 with latex (math preview window) and it should work better.

I made this plugin long time ago (when ckeditor4 was released, at least one year) but never published it.

It needs beta testers, so please report any bug.

Best regards.

Thibault

\begin{array}

\end{array}

environment , for example as in this question:

Looking at $5D$ Kaluza-Klein theory, the Kaluza-Klein metric is given by

$$g_{mn} = \left( \begin{array}{cc} g_{\mu\nu} & g_{\mu 5} \\ g_{5\nu} & g_{55} \\ \end{array} \right)$$

In the markdown math editor (https://github.com/thibaultduponchelle/q2a-markdown-editor-latex) or the wysiwyg math editor (https://github.com/thibaultduponchelle/q2a-wysiwyg-matheditor) ?

Markdown math editor is broken as of today (and never worked perfectly), please try wysiwyg matheditor instead.