18. Degree of maps between oriented manifolds - Pierre Albin

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  • čas přidán 2. 01. 2019
  • Lecture 18 of Algebraic Topology course by Pierre Albin.

Komentáře • 4

  • @mahhagogo
    @mahhagogo Před 3 lety +1

    I would love to watch any video lectures on differential geometry or topology by this professor, if any were available.

  • @fernandojackson7207
    @fernandojackson7207 Před 4 lety

    So the degree of z^k between S^1--> S^1 (the circle/1-sphere) is then k , right? The generator is S^1 itself, a single loop and z^k wraps around k times , and k-times is the class k[S^1]. Is that correct?

    • @ethanzell4073
      @ethanzell4073 Před 4 lety +2

      Yes. The degree of the map S^1\to S^1 given by z\mapsto z^k is k. You're also correct that this would correspond to multiplication by k under the isomorphism with \Z. Pedantic point: you may want to switch up the notation for your generator just to be clearer. Instead of saying S^1, maybe say the 1-simplex \sigma or something like that.

    • @fernandojackson7207
      @fernandojackson7207 Před 4 lety +1

      @@ethanzell4073 Thanks Ethan, nice presentation.