Half-iterate exp(z)-1: hypothese on growth of coefficients
#13
oh and ofcourse there is also the following idea :

define g(g(x)) = exp(x) - 1.

solve in the usual way at the parabolic fixpoint ( from julia )

now take the taylor expansion at x = 1 

so we arrive at

g(x) = sum a_n (x-1)^n

where the a_n are from the taylor expansion at 1.

Now expand ( use binomium ) to get 

g(x) = sum a_n (x-1)^n = sum b_n x^n

this might help to prove the bounds.


Not 100 % sure this works though since we are at the edge of convergeance ...

A combination with the integral idea from above might be fruitful.


regards

tommy1729
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Messages In This Thread
RE: Half-iterate exp(z)-1: hypothese on growth of coefficients - by tommy1729 - 08/06/2022, 10:14 PM
RE: Parabolic Formal Powerseries - by tommy1729 - 09/09/2022, 12:24 AM

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