cooperad the dual notion of operad

Pursuing Classifying Topoi

(This post will outline the haze of thoughts and visions as we pursue Classifying Topoi. All facts stated are true modulo small lies . Allegories to be taken with a liberal pinch of bath salts. It will be wordy to boot, TeXing reserved for better days and better keyboards.)

  1. We want to “classify” certain kinds of “structures” over a space/category/topos. Classifying means the following:
    • For every kind of structure we are interested in, there exists a special space, called (and denoted here) the Classifying Spåce for that structure.
    • Q: What kind of structures can be classified?
      A: Something something representable.

    • Probing the Classifying Space with a map from a Test Space corresponds to/yields a structure over the Test Space.
    • examples of structures: cohomology operations, nth cohomology, principal G-bundles, vector bundles etc. Each of these has a glorified Classifying Space.