See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/263469351 ABOUT WHAT IS CALLED "GUMOWSKI-MIRA MAP" Technical Report · June 2014 CITATIONS READS 0 1,428 1 author: Christian Mira Free researcher, after retirement, no affiliation 312 PUBLICATIONS 3,246 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Nonlinear Dynmics and Applications View project Phase locked loop View project All content following this page was uploaded by Christian Mira on 29 June 2014. The user has requested enhancement of the downloaded file. ABOUT WHAT IS CALLED "GUMOWSKI-MIRA MAP" Christian Mira Email : [email protected] The term "Gumowski Mira map" was never used by the two authors who have studied the equations so designated. Such an attitude would have been contrary to scientific ethics. A web search based on operative words "Gumowski Mira map" shows that several authors have found here a subject of articles, mainly related to "esthetical" images of chaotic solutions generated by these Dim2 nonlinear maps. In particular, samples of these images can be found via the link https://www.google.fr/search?q=Gumowski+Mira+map&es_sm=93&tbm=isch&tbo=u&sourc e=univ&sa=X&ei=0uCvU_OcDqKa0QXqk4HYCw&ved=0CC0QsAQ&biw=1164&bih=645 and also the video http://www.youtube.com/watch?v=AdcTAYLgYFI It is in the framework of the international colloquium "Points Mappings and Applications" (French title "Transformations Ponctuelles et leurs Applications") [1] that I announced an exhibition of "stochastic" (i.e. chaotic, at that time this adjective did not exist) images, quoting the Birkhoff's papers dealing with the laws of aesthetic (vol.3 of [3], p. 320-364), and a Poincaré's text extracted from a "Notice sur Halphen" [Journal de l'Ecole Polytechnique 60, 137-161 (1890)], also cf. [4]. In this text Poincaré deals with the aesthetic emotion which can be communicated by mathematics in the following terms: "Le savant digne de ce nom, le géomètre surtout, éprouve en face de son œuvre la même impression que l'artiste; sa jouissance est aussi grande et de même nature. Si je n'écrivais pour un public amoureux de la Science, je n'oserais pas m'exprimer ainsi; je redouterais l'incrédulité des profanes. Mais ici, je puis dire toute ma pensée. Si nous travaillons, c'est moins pour obtenir ces résultats positifs auxquels le vulgaire nous croit uniquement attachés, que pour ressentir cette émotion esthétique et la communiquer à ceux qui sont capables de l'éprouver". I took the liberty of saying that exhibited images had begun to manifest such an emotion in a form opened not only to specialists as Poincaré said, but also to a general public (cf. [2], page 27), this due to the new possibilities offered by numerical simulations. Such images can be shown in chapter 8 (I. Gumowski and a Toulouse research group in the "prehistoric" times of chaotic dynamics) of the book [5], the cover of which represents one of such images. It appears that an originality of the 1973 Toulouse colloquium was the exhibition of chaotic images, generated by solutions of nonlinear maps. The same exhibition, entitled "Morphogénèse et Mathématiques", was organized by Marcel Barthes, Director of the "Alliance Française Rio de Janeiro-Centre" in the "Centre Culturel de la Maison de France", from May 8 to 30, 1975. Equations of the map As equation-creating of two-dimensional conservative maps, the general map was used (Jacobian J being J 1) : (a) x' = y+F(x), y' =-x+F(x'), Two forms of the nonlinear term F(x) were considered, called "bounded nonlinearities" : (b1) F(x)= x+ 2(1-)x2 / (1+ x2), Map (a-b1) with =-0.2 Map (a-b1) with =0.05 Map (a-b1) with =0.3 Map (a-b1) with =0.25 (b2) F(x)= x + (1-)x2 exp[(1-x2)/4]. The following form of dissipative maps, quasi-conservative maps if >0 is small, with a nonlinear damping term, were used for having given rise to interesting images (a') x' = y+y(1-y2 )+ F(x), y' =-x+F(x'), The corresponding results are the object of chapter 3 (conservative maps) and 4 (almost conservative maps) of the book [6], and chapter 5 of the book [7]. An abbreviated presentation of the results is given in chapter 8 of [5]. As far as I know these results, with the considered particular non-linear characteristics, were new at the time of their publications. Their application was made to two models of the longitudinal motion of particles in an accelerator Another variant (quartic form) of the above equations is given by the image below Chaotic Attractors of Dim2 Noninvertible Maps (1968-1975) They are not generated by what is called "Gumowski-Mira maps", but they were presented in the framework of the chaotic images exhibition related to the 1973 colloquium "Points Mappings and Applications" (French title "Transformations Ponctuelles et leurs Applications") [1] More details on the different types of attractors generated by noninvertible maps are given with references in chapter 4 (1996 book [13], pp. 185-337). References 1. Colloque International du CNRS n° 229: Transformations Ponctuelles et Applications (Toulouse Sept. 1973). Proceedings: Editions du CNRS Paris (1976) 2. Mira, C. : "Exposé d'Introduction". Colloque International du CNRS n° 229 Transformations Ponctuelles et Applications (Toulouse Sept. 1973), pp. 19-27. Proceedings: Editions du CNRS Paris, (1976) 3. Birkhoff, G.D. : Collected Mathematical Papers. Dover Publications, Inc., New York (1968) 4. Poincaré, H. : Oeuvres, Tome II. Gauthier-Villars, Paris (1916) 5. Abraham, R., Ueda Y. (Editors): The chaos avant-garde. Memories of the early days of chaos theory. World Scientific Series on Nonlinear Science. Series A 39 (2000) 6. Gumowski I., Mira, C.: Recurrences and discrete dynamic systems - An introduction. 250 pages. Lecture notes in mathematics n° 809, Springer Berlin (1980) 7. Gumowski I., Mira, C.: Dynamique chaotique. Transition ordre-désordre. Ed. Cépadués Toulouse (1980) 13. Mira, C., Gardini, L., Barugola, A., Cathala, J.C.: Chaotic Dynamics in two-dimensional noninvertible maps. World Scientific, Series A on Nonlinear Sciences, 20 (1996) View publication stats
