What is...the universal coefficient theorem?

Goal. Explaining basic concepts of algebraic topology in an intuitive way. This time. What is...the universal coefficient theorem? Or: Working integrally rocks. Disclaimer. Nobody is perfect, and I might have said something silly. If there is any doubt, then please check the references. Disclaimer. These videos are concerned with algebraic topology, and not general topology. (These two are not to be confused.) I assume that you know bits and pieces about general topology, but not too much, I hope. Slides. http://www.dtubbenhauer.com/youtube.html Website with exercises. http://www.dtubbenhauer.com/lecture-algtop-2021.html Universal coefficients. https://en.wikipedia.org/wiki/Universal_coefficient_theorem https://ncatlab.org/nlab/show/universal+coefficient+theorem https://www.math.uchicago.edu/~may/VIGRE/VIGRE2009/REUPapers/ChenJ.pdf Relation to quantum physics. https://link.springer.com/book/10.1007/978-3-319-46143-4 Tor. https://en.wikipedia.org/wiki/Tor_functor https://math.stackexchange.com/questions/16310/what-is-the-tor-functor Hatcher’s book (I sometimes steal some pictures from there). https://pi.math.cornell.edu/~hatcher/AT/AT.pdf Always useful. https://en.wikipedia.org/wiki/Counterexamples_in_Topology #algebraictopology #topology #mathematics