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Abstract Algebra | If G/Z(G) is cyclic then G is abelian.

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  • เผยแพร่เมื่อ 4 มี.ค. 2020
  • We prove a classic result that says if the quotient of a group by its center is cyclic then the group is abelian.
    www.michael-penn.net
    www.randolphcollege.edu/mathem...

ความคิดเห็น • 10

  • @charlesleninja
    @charlesleninja 7 หลายเดือนก่อน

    At 2:35 you needed to include the negative numbers as well when taking the union. When |xZ(G)| is finite you need not do this because (xZ(G))^-1 = (xZ(G))^n-1 where n = |xZ(G)| but when the order of the generator is infinite, you will never reach its inverse by repeating it. Otherwise great educationnal material, I'm going trhough Dummit & Foote's Abstract Algebra myself and did this exact problem some days ago. We have the exact same answer.
    Edit: As a (funny?) result from this, we get G/Z(G) = {1} becasue Z(G) = G since G is abelian, so we will never get a non-trivial cyclic group if we quotient a group by its center, making my correction obselete in hindsight.

  • @zappingabhishek4003
    @zappingabhishek4003 7 หลายเดือนก่อน

    at 3:40, we could add an extra explanation saying that x^n*y*x^m*z could be written as x^(n+m)*y*z because y belongs to Z(G), and hence y*a=a*y for every 'a' belonging to G. (I had a hard time getting this step).

  • @hyperduality2838
    @hyperduality2838 ปีที่แล้ว

    Subspace topology is dual to quotient topology.
    Elliptic curves are dual to modular forms.
    "Always two there are" -- Yoda.

  • @revathymohans3053
    @revathymohans3053 3 ปีที่แล้ว +1

    Really superb sir..thanks a lot for this video

  • @Black_white_you
    @Black_white_you 2 ปีที่แล้ว

    thanks a lot!

  • @esturion001
    @esturion001 3 ปีที่แล้ว

    Thanks

  • @francineochoaf.160
    @francineochoaf.160 3 ปีที่แล้ว

    thaks a lot

  • @annjulius4282
    @annjulius4282 3 ปีที่แล้ว

    Great video sir

  • @juliangonzalez8997
    @juliangonzalez8997 2 ปีที่แล้ว

    Thanks