Abstract
We investigate how large a set can be on which a continuous nowhere monotone function is one-to-one. We consider the σ-ideal of microscopic sets, which is situated between the countable sets and the sets of Hausdorff dimension zero and prove that the typical function in C[0, 1] (in the sense of Baire) is nowhere monotone and one-to-one except on some microscopic set. We also give an example of a continuous nowhere monotone function of bounded variation on [0, 1], which is one-to-one except on some microscopic set, so it is not a typical function.
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References
J. Appell, Insiemi ed operatori “piccoli” in analisi funzionale, Rend. Ist. Mat. Univ. Trieste, 33 (2001), 127–199.
J. Appell, E. D’Aniello and M. Vath, Some remarks on small sets, Ricerche di Matematica, 50 (2001), 255–274.
S. J. Agronsky, A. M. Bruckner and M. Laczkovich, Dynamics of typical continuous function, J. London Math. Soc., 40 (1989), 227–243.
A. M. Bruckner, J. B. Bruckner and B. S. Thomson, Real Analysis, Prentice-Hall (New Jersey, 1997).
J. B. Brown, U. B. Darji and E. P. Larsen, Nowhere monotone functions and functions of nonmonotonic type, Proc. Amer. Math. Soc., 127 (1999), 173–182.
A. M. Bruckner and K. M. Garg, The level structure of a residual set of continuous functions, Trans. Amer. Math. Soc., 232 (1977), 307–321.
Z. Buczolich and A. Máthé, Where are typical C 1 functions one-to-one, Math. Bohem., 131 (2006), 291–303.
K. M. Garg, On nowhere monotone functions. I. Derivates at residual set, Ann. Univ. Sci. Budapest, Sect. Math., 5 (1962), 173–177.
K. M. Garg, On nowhere monotone functions. II. Derivates at sets of power c and at sets of positive measure, Rev. Math. Pures Appl., 7 (1962), 663–671.
K. M. Garg, On nowhere monotone functions. III (Function of first and second species), Rev. Math. Pures Appl., 8 (1963), 83–90.
K. M. Garg, On level sets of a continuous nowhere monotone function, Fund. Math., 52 (1963), 59–68.
A. Karasińska, The one-to-one restrictions of functions, Tatra Mt. Math. Publ., to appear.
S. Marcus, Sur les fonctions continues qui ne sont monotones en aucun intervalle, Rev. Math. Pures Appl., 3 (1958), 101–105.
J. C. Oxtoby, Measure and Category, Springer-Verlag (New York, Heidelberg, Berlin, 1980).
K. Padmavally, On the roots of equation f(x) = ξ where f(x) is real and continuous in (a, b), Proc. Amer. Math. Soc., 4 (1953), 839–841.
C. C. Pugh, Real Mathematical Analysis, Springer-Verlag (New York, Berlin, Heidelberg, 2002).
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Karasińska, A., Wagner-Bojakowska, E. Nowhere monotone functions and microscopic sets. Acta Math Hung 120, 235–248 (2008). https://doi.org/10.1007/s10474-008-7093-y
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DOI: https://doi.org/10.1007/s10474-008-7093-y