Étale space of continuous functions

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Definition

Let X and Y be topological spaces. The étale space of continuous functions at X is a topological space along with an étale map down to X, which arises from the sheaf of continuous functions from X to Y. Some explicit aspects of this map:

  • The fiber of the map at any point xX, is the set of germs, at x, of continuous functions from open neighbourhoods of X to Y. In other words, it is the stalk at x for the sheaf of continuous functions.
  • The topology on the étale space is given as follows: for every continuous function f from an open subset U of X to Y, the set of germs of f at points of X is deemed to be an open subset. We now treat these open subsets as a subbasis for the topology of the étale space.