File:Braid-modular-group-cover.svg

Summary

Description
English: Commutative diagram showing the braid group B3 as the universal central extension of the modular group, sitting as lattices inside SL2(R) and its universal cover.
Date
Source Own work, created as per: en:meta:Help:Displaying a formula#Commutative diagrams; source code below.
Author Nils R. Barth
Permission
(Reusing this file)
Nils R. Barth, the copyright holder of this work, hereby publishes it under the following license:
Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.
Category:Self-published work#Braid-modular-group-cover.svgCategory:PD-self#Braid-modular-group-cover.svg
Category:Self-published work

LaTeX source

\documentclass{amsart}
\usepackage[all, ps, dvips]{xy} % Loading the XY-Pic package
                                % Using postscript driver for smoother
                                % curves
\usepackage{color}              % For invisible frame
\DeclareMathOperator{\SL}{SL}
\DeclareMathOperator{\PSL}{PSL}
\begin{document}
\thispagestyle{empty} % No page numbers
\SelectTips{eu}{}     % Euler arrowheads (tips)
\setlength{\fboxsep}{0pt} % Frame box margin
{\color{white}\framebox{{\color{black}$$ % Frame for margin

\xymatrix@R=6pt{
  & B_3  \ar@{->>}[r]  \ar@{^(->}[dd]
  & \PSL_2(\mathbf{Z}) \ar@{^(->}[dd]\\
\mathbf{Z} \ar@{_(->}@/^/[ur] \ar@{^(->}@/_/[dr] \\
  & \overline{\SL_2(\mathbf{R})} \ar@{->>}[r]
  & \PSL_2(\mathbf{R})
}

$$}}} % end math, end frame
\end{document}

Licensing

Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.
Category:Self-published work#Braid-modular-group-cover.svgCategory:PD-self#Braid-modular-group-cover.svg Category:SVG commutative diagrams Category:Braid theory Category:Xy-pic graphics Category:Images with LaTeX source code Category:Linear groups
Category:Braid theory Category:Images with LaTeX source code Category:Linear groups Category:PD-self Category:SVG commutative diagrams Category:Self-published work Category:Xy-pic graphics