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the normal form of Hopf bifurcation

Bo
2016-12-09
2016-12-09
  • Bo

    Bo - 2016-12-09

    We can get the first lyapunov coefficient of Hopf bifurcation by using MatCont.There I have a quite general question:
    When I get the information about Hopf bifurcation which are printed in the MatLab command window:
    label=H,x=(0.015189 -5.254172 -0.001297 0.074389 126.942956)
    First Lyapunov coefficient=-9.231096e+01
    Now,I want to get the coefficients of normal form in the vicinity of the Hopf bifurcation which are a,aa,c,cc as the following shows
    A'=a(b-126.942956)A+cA^3
    B'=aa
    (b-126.942956)+cc*A^2
    where A is a measure of the amplitude of the born limit cycle
    Is it possible in MatCont to get them(a,aa,c,cc),or other ways?
    Thank you in advance,

     

    Last edit: Bo 2016-12-09
    • hilmeijer

      hilmeijer - 2016-12-09

      Dear Bo,

      I am not entirely sure I understand your form (A',B') and whether it is correct. You cannot get them immediately. I can see that with some effort one could get such coefficients from adapting code in init_HH_NS1.m as this script involves the required multilinear forms. But this requires some dedicated programming and center manifold reduction techniques.

      Best, Hil


      From: Bo Zhu zbscorpion@users.sf.net
      Sent: Friday, December 9, 2016 10:06 AM
      To: [matcont:discussion]
      Subject: [matcont:discussion] the normal form of Hopf bifurcation

      We konw the first lyapunov coefficient of Hopf bifurcation by using MatCont.There I have a quite general questions:
      When I get the information about Hopf bifurcation which are printed in the MatLab command window:
      label=H,x=(0.015189 -5.254172 -0.001297 0.074389 126.942956)
      First Lyapunov coefficient=-9.231096e+01
      Now,I want to get the coefficients of normal form in the vicinity of the Hopf bifurcation which are a,aa,c,cc as the following shows
      A'=a(b-126.942956)A+cA^3
      B'=aa
      (b-126.942956)+cc*A^3
      Is it possible in MatCont to get them(a,aa,c,cc),or other ways?
      Thank you in advance


      the normal form of Hopf bifurcation


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      • Bo

        Bo - 2016-12-09

        A is r,B is \theta
        A'=a(b-126.942956)A+cA^3
        B'=aa
        (b-126.942956)+cc*A^2
        The above formulas which reduce four-dimensional system are getted by using the method of multiple scales

         
  • Bo

    Bo - 2016-12-09
     

    Last edit: Bo 2016-12-09

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