Superfunctions



Superfunctions is book, English remake of the Russian book Суперфункции, (since 2014).

The book describes evaluation of abelfunctions, superfunctions, and the non-integer iterates. In particular, results for tetration, arctetration and iterates of exponential are presented.

The English version is loaded as https://mizugadro.mydns.jp/BOOK/444.pdf

Covers
At the front cover, the complex map of natural tetration is shown.

The following topics are indicated: Non-integer iterates of holomorphic functions. Tetration and other superfunctions. Formulas, algorithms, tables, graphics and complex maps.

The back cover suggests short abstract of the Book and few notes about the Author.

About the topic
Assume some given holomorphic function \(T\). The superfunction is holomorphic solution F of equation \(T(F(z))=F(z+1)\)

The Abel function (or abelfunction) is the inverse of superfunction, \(G=F^{-1}\)

The abelfunction is solution of the Abel equation \(G(T(z))=G(z)+1\)

As the superfunction \(F\) and the abelfunction \(G=F^{-1}\) are established, the \(n\)th iterate of transfer function \(T\) can be expressed as follows: \(T^n(z)=F(n+G(z))\)

This expression allows to evaluate the non-integer iterates. The number n of iterate can be real or even complex. In particular, for integer \(n\), the iterates have the common meaning: \(T^{-1}\) is inverse function of \(T\), \(T^0(z)=z\), \(T^1(z)=T(z)\), \(T^2(z)=T(T(z)) \), \(T^3(z)=T(T(T(z))) \), and so on. The group property holds: \(T^m(T^n(z))=T^{m+n}(z)\)

The book is about evaluation of the superfunction \(F\), the abelfunction \(G\) and the non-integer iterates of various transfer functions \(T\).

The special notation is used in through the book; the number of iterate is indicated as superscript. For example, In these notations, \(\sin^2(z)=\sin(\sin(z))\), but never \(\sin(z)^2\). This notation is borrowed from the Quantum mechanics, where \(P^2(\psi)=P(P(\psi))\), but never \(P(\psi)^2\).

About the Book
Tools for evaluation of superfunctions, abelfunctions and non-integer iterates of holomorphic functions are collected. For a giver transfer function T, the superfunction is solution F of the transfer equation F(z+1)=T(F(z)). The abelfuction is inverse of F. In particular, thesuperfunctions of factorial, exponent, sin; the holomorphic extensions of the logistic sequence and of the Ackermann functions are suggested. from ackermanns, the tetration (mainly to the base b>1) and pentation (to base e) are presented. The efficient algorithm for the evaluation of superfunctions and abelfunctions are described. The graphics and complex maps are plotted. The possible applications are discussed. Superfunctions significantly extend the set of functions that can be used in scientific research and technical design. Generators of figures are loaded to the site TORI, http://mizugadro.mydns.jp for the free downloading. With these generators, the Readers can reproduce (and modify) the figures from the Book. The Book is intended to be applied and popular. I try to avoid the complicated formulas, but some basic knowledge of the complex arithmetics, Cauchi integral and the principles of the asymptotical analysis should help at the reading.

About the Author
Dmitrii Kouznetsov

Graduated from the Physics Department of the Moscow State University (1980). Work: USSR, Mexico, USA, Japan. Century 20: Proven the quantum stability of the optical soliton, suggested the low bound of the quantum noise of nonlinear amplifier, indicated the limit of the single mode approximation in the quantum optics. Century 21: Theorem about boundary behaviour of modes of Dirichlet laplacian, Theory of ridged atomic mirrors, formalism of superfunctions, TORI axioms.

Summary
The summary suggests main notations used in the Book:

\(T\)\( ~ ~ ~ ~ ~\) Transfer function

\(T\big(F(z)\big)=F(z\!+\!1)\) \(~ ~ ~\) Transfer equation, superfunction

\(G\big(T(z)\big)=G(z)+1\) \(~ ~ ~\) Abel equation, abelfunction

\(F\big(G(z)\big)=z\) \(~ ~ ~ ~ ~\) Identity function

\(T^n(z)=F\big(n+G(z)\big)\) \(~ ~ ~\) \(n\)th iterate

\(\displaystyle F(z)=\frac{1}{2\pi \mathrm i} \oint \frac{F(t) \, \mathrm d t}{t-z}\) \(~ ~ ~\) Cauchi integral

\(\mathrm{tet}_b(z\!+\!1)=b^{\mathrm{tet}_b(z)}\) \(~ ~ ~\) tetration to base \(b\)

\(\mathrm{tet}_b(0)=1\) \(~, ~ ~\) \( \mathrm{tet}_b\big(\mathrm{ate}_b(z)\big)=z\)

\(\mathrm{ate}_b(b^z)=\mathrm{ate}_b(z)+1\) \(~ ~\) arctetration to base \(b\)

\(\exp_b^{~n}(z)=\mathrm{tet}_b\big(n+\mathrm{ate}_b(z)\big)\) \(~ ~\) \(n\)th iterate of function \(~\) \(z\!\mapsto\! b^z\)

\(\displaystyle \mathrm{Tania}^{\prime}(z)=\frac{\mathrm{Tania}(z)}{\mathrm{Tania}(z)\!+\!1}\) \(~ ~\)  Tania function,\(~\)  \(\mathrm{Tania}(0)\!=\!1\)

\(\displaystyle \mathrm{Doya}(z)=\mathrm{Tania}\big(1\!+\!\mathrm{ArcTania}(z)\big)\) \(~ ~\) Doya function

\(\displaystyle \mathrm{Shoka}(z)=z+\ln(\mathrm e^{-z}\!+\!\mathrm e \!-\! 1)\) \(~\) Shoka function

\(\displaystyle \mathrm{Keller}(z)=\mathrm{Shoka}\big(1\!+\!\mathrm{ArcShoka}(z)\big)\) \(~ ~\) Keller function

\(\displaystyle \mathrm{tra}(z)=z+\exp(z)\) \(~ ~ ~\) Trappmann function

\(\displaystyle \mathrm{zex}(z)=z\,\exp(z)\) \(~ ~ ~ ~\) Zex function

\(\displaystyle \mathrm{Nem}_q(z)=z+z^3+qz^4\) \(~ ~ ~ ~\) Nemtsov function

Recent advance
Most of results presented in the book, are published in scientific journals; the links (without numbers) are supplied at the bottom.

After the appearance of the first version of the Book, certain advances are observed about evaluation of tetration of complex argument; the new algorithm is suggested, that seems to be mode efficient, than the Cauchi integral described in the Book.

Keywords
Abel function, Book, Doya function, Iteration, Keller function, Maple and tea, LambertW, Shoka function, Superfunction, SuperFactorial, SuSin, SuTra, SuZex, Tania function, Tetration, Trappmann function, Tetration, Zex function,