Hyperspaces in topological Categories

Abstract

Hyperspaces form a powerful tool in some branches of mathematics: lots of fractal and other geometric objects can be viewed as fixed points of some functions in suitable hyperspaces - as well as interesting classes of formal languages in theoretical computer sciences, for example (to illustrate the wide scope of this concept). Moreover, there are many connections between hyperspaces and function spaces in topology. Thus results from hyperspaces help to get new results in function spaces and vice versa. Unfortunately, there ist no natural hyperspace construction known for general topological categories (in contrast to the situation for function spaces). We will shortly present a rather combinatorial idea for the transfer of structure from a set $X$ to a subset of $\mathfrak{P}(X)$, just to motivate an interesting question in set theory. Then we will propose and discuss a new approach to define hyperstructures, which works in every cartesian closed topological category, and so applies to every topological category, using it's topological universe hull.