# How to draw an Auslander-Reiten quiver?

Please, help me in typesetting the following diagram, I'm not an expert in drawing with LaTeX.

I have used the advice of the excellent user @egreg. You can change the tip of the vectors by looking at this link: Is it possible to change the size of an arrowhead in TikZ/PGF?. I believe that the diagram that uses the arrows in that way is from the package xymatrix.

\documentclass{article}
\usepackage{newtxtext,newtxmath}
\usepackage{tikz-cd,amssymb}

\begin{document}

\begin{tikzcd}[column sep=huge,row sep=small]
1 \arrow[rd, "\alpha"] \\ & 3 & 4 \arrow[l, "\gamma"'] \\
2 \arrow[ru, "\beta"'] \end{tikzcd}

\end{document}

\documentclass{article}
\usepackage{newtxtext,newtxmath}
\usepackage{tikz-cd,amssymb}
\newcommand{\pmat}[4]{\begin{pmatrix} #1 & #2 \\ #3 & #4\end{pmatrix}}
\begin{document}

\begin{tikzcd}[column sep=huge,row sep=small]
1 \arrow[rd, "\pmat{-1}{5}{5}{1}"] \\ & 3 & 4 \arrow[l, "\gamma"'] \\
2 \arrow[ru, "\beta"'] \end{tikzcd}

\end{document}

SECOND ADDENDUM From a suggestion of @Bernard's comment I have added psmallmatrix environment (from mathtools).

\documentclass{article}
\usepackage{newtxtext,newtxmath,mathtools}
\usepackage{tikz-cd,amssymb}
\newcommand{\smat}[4]{\begin{psmallmatrix} #1 & #2 \\ #3 & #4\end{psmallmatrix}}
\begin{document}

\begin{tikzcd}[column sep=huge,row sep=small]
1 \arrow[rd, near start, "\smat{-1}{5}{5}{1}"] \\ & 3 & 4 \arrow[l, "\gamma"'] \\
2 \arrow[ru, "\beta"'] \end{tikzcd}

\end{document}
• it was wonderful. Thank you for your help @egreg – tuce Jun 18 '18 at 21:28
• how can I write matrices instead of alpha, gamma, beta on arrows @egreg , – tuce Jun 18 '18 at 21:36
• how can I write matrices instead of alfa beta gamma on arrows @sebastiano – tuce Jun 18 '18 at 21:38
• on the same diagram you could write on the arrows as a matrix. – tuce Jun 18 '18 at 21:49
• no problem @sebastion you are perfect :) – tuce Jun 18 '18 at 22:32