Galois group of x^4-20x^2+80

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  • Опубліковано 24 лип 2024
  • As suggested by Bjorn Carlsson, here is the splitting field and Galois group of x^4-20x^2+80.

КОМЕНТАРІ • 10

  • @bjorncarlsson787
    @bjorncarlsson787 4 місяці тому +1

    So interesting!

  • @depressedguy9467
    @depressedguy9467 5 днів тому

    Hey bro, need some algebraic topology, moduler forms

  • @depressedguy9467
    @depressedguy9467 5 днів тому

    Try to make video to find intermediate fields

  • @Elstupidofood
    @Elstupidofood 4 місяці тому +1

    👍

  • @janni7439
    @janni7439 2 місяці тому

    Hate the fact that to estimate the gailois group, one has to actually solve the polynomial. What is it worth then to calculate the group?

    • @coconutmath4928
      @coconutmath4928  2 місяці тому

      In this case it's the most straightforward way. If you're talking about computational complexity, then I believe some algorithms still factor the polynomial to compute the group, so I don't know if there's a way around it in general.

  • @user-jm6rm2xn3z
    @user-jm6rm2xn3z 4 місяці тому

    sir what is the point of the galois theory it can't give us exact or approximated solution

    • @coconutmath4928
      @coconutmath4928  2 місяці тому +1

      Can you clarify this? We did find the automorphisms of G explicitly.

    • @user-jm6rm2xn3z
      @user-jm6rm2xn3z 2 місяці тому

      @@coconutmath4928 i mean why we use the galois group for example to solve a cubic equation when we can solve it easily using cardon's method which involve the real and imaginary solutions

    • @matthewbyrne6344
      @matthewbyrne6344 Місяць тому

      The point of Galois theory is not to find the solutions of polynomials, but rather to find intermediate fields in a (finite) Galois extension. For example, in this case we know there is only one intermediate field ℚ ⊂ M ⊂ K, since the Galois group ℤ/4ℤ only has one proper nontrivial subgroup.
      I feel like a lot of expository material focuses a lot on the insolubility of the quintic. While this is an elegant application of the theory, thinking that is all kind of misses the point.