We collect and generalize various known definitions of principal iteration semigroups in the case of multiplier zero and establish connections among them. The common characteristic property of each definition is conjugating of an iteration semigroup to different normal forms. The conjugating functions are expressed by suitable formulas and satisfy either Böttcher’s or Schröder’s functional equation.
[1] Blanton G., Baker J.A., Iteration groups generated by C n functions, Arch. Math. (Brno), 1982, 18(3), 121–127
[2] Ger J., Smajdor A., Regular iteration in the case of multiplier zero, Aequationes Math., 1972, 7, 127–131 http://dx.doi.org/10.1007/BF01818507
[3] Kuczma M., Functional Equations in a Single Variable, Monogr. Mat., 46, PWN, Warszawa, 1968
[4] Kuczma M., Choczewski B., Ger R., Iterative Functional Equations, Encyclopedia Math. Appl., 32, Cambridge University Press, Cambridge, 1990 http://dx.doi.org/10.1017/CBO9781139086639
[5] Szekeres G., Regular iteration of real and complex functions, Acta Math., 1958, 100, 203–258 http://dx.doi.org/10.1007/BF02559539
[6] Targonski Gy., Topics in Iteration Theory, Studia Math.: Skript, 6, Vandenhoeck & Ruprecht, Göttingen, 1981
[7] Weitkämper J., Embeddings in iteration group and semigroups with nontrivial units, Stochastica, 1983, 7(3), 175–195
[8] Zdun M.C., On the regular solutions of a linear functional equation, Ann. Polon. Math., 1974, 30, 89–96
[9] Zdun M.C., Some remarks on iteration semigroups, Uniw. Slaski w Katowicach Prace Naukowe-Prace Mat., 7, 1977, 65–69
[10] Zdun M.C., Continuous and Differentiable Iteration Semigroups, Prace Nauk. Uniw. Slask. Katowic., 308, Uniwersytet Slaski, Katowice, 1979
[12] Zdun M.C., On the structure of iteration group of homeomorphisms having fixed points, Aequationes Math., 1998, 55(3), 199–216 http://dx.doi.org/10.1007/s000100050030
[13] Zdun M.C., Zhang W., Koenigs embedding flow problem with global C 1 smoothness, J. Math. Anal. Appl., 2011, 374(2), 633–643 http://dx.doi.org/10.1016/j.jmaa.2010.08.075