The Brin-Thompson groups sV are of type F_\infty
  We prove that the Brin-Thompson groups sV, also called higher dimensional Thompson's groups, are of type F_\infty for all natural numbers s. This result was previously shown for s up to 3, by considering the action of sV on a naturally associated space. Our key step is to retract this space to a subspace sX which is easier to analyze. 
Martin Fluch, Marco Marschler, Stefan Witzel, Matthew C. B. Zaremsky
math.GR math.GT