The problem of the existence of extension maps from 0 to ℝ in the setting of the classical ultradifferentiable function spaces has been solved by Petzsche [9] by proving a generalization of the Borel and Mityagin theorems for -spaces. We get a Ritt type improvement, i.e. from 0 to sectors of the Riemann surface of the function log for spaces of ultraholomorphic functions, by first establishing a generalization to some nonclassical ultradifferentiable function spaces.
@article{bwmeta1.element.bwnjournal-article-smv143i3p221bwm, author = {Jean Schmets and Manuel Valdivia}, title = {Extension maps in ultradifferentiable and ultraholomorphic function spaces}, journal = {Studia Mathematica}, volume = {141}, year = {2000}, pages = {221-250}, zbl = {0972.46013}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-smv143i3p221bwm} }
Schmets, Jean; Valdivia, Manuel. Extension maps in ultradifferentiable and ultraholomorphic function spaces. Studia Mathematica, Tome 141 (2000) pp. 221-250. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-smv143i3p221bwm/
[000] [1] E. Borel, Sur quelques points de la théorie des fonctions, Ann. Sci. Ecole Norm. Sup. 12 (1895), 9-55. | Zbl 26.0429.03
[001] [2] J. C. Canille, Desenvolvimento asintotico e introduç ao as cálculo diferential resurgente, 17 Colóquio Brasileiro de Matemática, IMPA, 1989.
[002] [3] H. Cartan, Sur les classes de fonctions définies par des inégalités portant sur leurs dérivées successives, Actualités Sci. Indust. 867, Publ. Inst. Math. Univ. Clermont-Ferrand, Hermann, Paris, 1940. | Zbl 0061.11701
[003] [4] A. Gorny, Contribution à l'étude de fonctions dérivables d'une variable réelle, Acta Math. 71 (1939), 317-358. | Zbl 65.0216.01
[004] [5] A. Grothendieck, Produits tensoriels topologiques et espaces nucléaires, Mem. Amer. Math. Soc. 16 (1955).
[005] [6] L. Hörmander, The Analysis of Linear Partial Differential Operators, I, Springer, Berlin, 1983. | Zbl 0521.35001
[006] [7] S. Mandelbrojt, Séries Adhérentes, Régularisation des Suites, Applications, Collection de Monographies sur la Théorie des Fonctions, Gauthier-Villars, Paris, 1952.
[007] [8] B. Mityagin, Approximate dimension and bases in nuclear spaces, Uspekhi Mat. Nauk 16 (1961), no. 4, 63-132 (in Russian); English transl.: Russian Math. Surveys 16 (1961), 59-127.
[008] [9] H.-J. Petzsche, On E. Borel's theorem, Math. Ann. 282 (1988), 299-313. | Zbl 0633.46033
[009] [0] J. F. Ritt, On the derivatives of a function at a point, Ann. of Math. 18 (1916), 18-23. | Zbl 46.0471.02
[010] [1] J. C. Tougeron, An introduction to the theory of Gevrey expansions and to the Borel-Laplace transform with some applications, Course of 3rd Cycle, Univ. of Toronto.
[011] [2] G. Valiron, Théorie des fonctions, Masson, Paris, 1966.