Abstract
Most results on the polynomial-like iterative equation are given under the condition that the given function is monotone, while a work by L. Liu and X. Gong gets non-monotone PM solutions with height 1 when the given function is of the same case. Removing the condition on height for the given function, we first give a method to assert the nonexistence of C0 solutions, then present equivalent conditions for the existence of PM solutions with finite height. Finally, as an application of the equivalent conditions, we construct the PM solutions in the case that the given function has one fort.
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References
Babbage Ch. An essay towards the calculus of functions. Philos Trans, 1815, 105: 389–423
Babbage Ch. An essay towards the calculus of functions, II. Philos Trans, 1816, 106: 179–256
Baron K, Jarczyk W. Recent results on functional equations in a single variable, perspectives and open problems. Aequationes Math, 2001, 61: 1–48
Chen J, Zhang W. Leading coefficient problem for polynomial-like iterative equations. J Math Anal Appl, 2009, 349: 413–419
Editorial. Report of Meeting The 50th International Symposium on Functional Equations Hotel Aurum, Hajdúszoboszló (Hungary), June 17–24, 2012. Aequationes Math, 2013, 86 (3): 289–320
Gong X, Zhang W. Convex solutions of the polynomial-like iterative equation in Banach spaces. Publ Math Debrecen, 2013, 82: 341–348
Kuczma M. Functional Equations in a Single Variable. Monogr Math, Vol 46. PWN: Warsaw, 1968
Kuczma M, Choczewski B, Ger R. Iterative Functional Equations. Encyclopedia Math Appl, Vol 32. Cambridge: Cambridge University Press, 1990
Li X, Deng S. An iterative equation on the unit circle. Acta Math Sci, 2006, 26B(3): 541–550
Liu L, Gong X. The polynomial-like iterative equation for PM functions. Science China Mathematics, 2017, 60(8): 1503–1514
Ng C, Zhao H. Periodic and continuous solutions of a polynomial-like iterative equation. Aequationes Math, 2017, 91(1): 185–200
Si J. Existence of local analytic solutions of the iterative equation \(\sum\limits_{i = 1}^n {{\lambda _i}{f^i}\left( z \right) = F\left( z \right)} \). Acta Math Sinica, 1994, 37: 590–600 (in Chinese)
Zhang J, Yang L. Discussion on iterative roots of piecewise monotone functions. Acta Math Sinica, 1983, 26: 398–412 (in Chinese)
Zhang J, Yang L, Zhang W. Some advances on functional equation. Adv Math (in Chinese), 1995, 24: 385–405
Zhang P, Li W. Height and topological conjugacy of piecewise monotone functions. Acta Math Sinica, 2018, 2(61): 243–260 (in Chinese)
Zhang W. Discussion on the iterated equation \(\sum\limits_{i = 1}^n {{\lambda _i}{f^i}\left( x \right) = F\left( x \right)} \). Chinese Sci Bull, 1987, 32: 1444–1451
Zhang W. Solutions of equivariance for a polynomial-like iterative equation. Proc Roy Soc Edinburgh Sect, Sect A, 2000, 130: 1153–1163
Zhang W, Xu B. Algebraic approach to equivariance of solutions for an iterative equation. Publ Math Debrecen, 2008, 72(1/2): 189–198
Zhang W, Xu B, Zhang W. Global solutions for leading coefficient problem of polynomial-like iterative equations. Results Math, 2013, 63: 79–93
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The first author is supported by the Natural Science Foundation of Shandong Province (ZR2017MA019) and the Scientific Research Fund of Binzhou University (BZXYL1802); the second author is supported by the National Science Foundation of China (11501394), the Science Research Fund of Sichuan Provincial Education Department (15ZB0041) and funding of School of Mathematical Sciences and V.C. & V.R. Key Lab of Sichuan Province.
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Zhang, P., Zeng, Y. A generalized result on the polynomial-like iterative equation. Acta Math Sci 41, 177–186 (2021). https://doi.org/10.1007/s10473-021-0110-8
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DOI: https://doi.org/10.1007/s10473-021-0110-8