# Curved arrows between two circles

I'm wondering if it's possible to make this sort of diagram in Latex:

This question seems like a good place to start, but I don't see how to replace the nodes with circles. Also, I couldn't find any instructions for making the marks on the perimeter of the circle, as in my drawing. Thanks for any help!

• You could start with \draw (0, 0) circle (2cm); to draw a circle. Commented Feb 5, 2016 at 5:24
• Have you tried with the tikz package ? Commented Feb 5, 2016 at 6:32
• Yes, I know that one can make circles and arrows with Tikz, but I can't get the positioning right Commented Feb 5, 2016 at 15:48

\documentclass[french]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[a4paper]{geometry}
\usepackage{babel}
\usepackage{amsmath,amsthm, amssymb, latexsym}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\draw[thick] (0cm,0cm) circle(1cm);
\draw[thick] (3cm,0cm) circle(1cm);
\path node[anchor=south] at (0,1) {e};
\path node[anchor=north] at (0,-1) {b};
\path node[anchor=east] at (-1,0) {ab};
\path node[anchor=west] at (1,0) {a};
\path node[anchor=south] at (3,1) {eH};
\path node[anchor=north] at (3,-1) {bH};
\path[->] (-1,0) edge [out=-120, in=220] (3,-1);
\path[->] (0,-1) edge [out=-20, in=200] (3,-1);
\path[->] (0,1) edge [out=20, in=-200] (3,1);
\path[->] (1,0) edge [out=40, in=170] (3,1);
\end{tikzpicture}
\end{document}

• There might be other ways, easier or more beautiful. Anyway, this code works. I wanted to name the defined nodes (for example, the node at (0,1) could be named as "e", it would be easier to plot the arrows later). I didn't remember how to do that, that's why I had to repeat the coordinates again, which can lead to errors. Commented Feb 5, 2016 at 7:10
• Thanks! It looks good. Is the "french" part of the document class necessary? Which package uses it? Commented Feb 5, 2016 at 15:49
• No it's not. You didn't put a MWE, so I took one of mine. And because I'm french, I automatically load the french option. I also think babel package is not needed. Commented Feb 5, 2016 at 17:17
• Great, thanks for the help! I only ask because it seemed to conflict with another package I was using Commented Feb 5, 2016 at 17:50
• You can also remove babel, amsmath, amsthm, amssymb, latexsym and tikz packages. Commented Feb 5, 2016 at 18:24