Previous |  Up |  Next

Article

Keywords:
Fourier series; universal functions; Landau's extremal functions
Summary:
We prove the existence of functions $f\in A(\mathbb D)$, the Fourier series of which being universally divergent on countable subsets of $\mathbb T = \partial \mathbb D$. The proof is based on a uniform estimate of the Taylor polynomials of Landau's extremal functions on $\mathbb T\setminus\{1\}$.
References:
[1] Anderson J.M., Clunie J., Pommerenke Ch.: On Bloch functions and normal functions. J. Reine Angew. Math. 270 (1974), 12–37. MR 0361090 | Zbl 0292.30030
[2] Beise H.-P., Müller J.: On the boundary behaviour of Taylor series in Hardy and Bergman spaces. preprint, 2014.
[3] Bernal-González L.: Lineability of universal divergence of Fourier series. Integral Equations Operator Theory 74 (2012), 271–279. DOI 10.1007/s00020-012-1984-6 | MR 2983066 | Zbl 1282.47008
[4] Fejér L.: Über die Koeffizientensumme einer beschränkten und schlichten Potenzreihe. Acta Math. 49 (1926), 183–190. DOI 10.1007/BF02543853 | MR 1555240
[5] Grosse-Erdmann K.-G.: Universal families and hypercyclic operators. Bull. Amer. Math. Soc. (N.S.) 36 (1999), 345–381. DOI 10.1090/S0273-0979-99-00788-0 | MR 1685272 | Zbl 0933.47003
[6] Grosse-Erdmann K.-G., Peris Manguillot A.: Linear Chaos. Universitext, Springer, London, 2011. MR 2919812 | Zbl 1246.47004
[7] Kahane J.-P.: Baire's category theorem and trigonometric series. J. Anal. Math. 80 (2000), 143–182. DOI 10.1007/BF02791536 | MR 1771526 | Zbl 0961.42001
[8] Katsoprinakis E., Nestoridis V., Papachristodoulos C.: Universality and Cesàro summability. Comput. Methods Funct. Theory 12 (2012), 419–448. MR 3058515 | Zbl 1262.30071
[9] Landau E., Gaier D.: Darstellung und Begründung einiger neuerer Ergebnisse der Funktionentheorie. Springer, Berlin, 1986. MR 0869998 | Zbl 0601.30001
[10] Müller J.: Continuous functions with universally divergent Fourier series on small subsets of the circle. C.R. Math. Acad. Sci. Paris 348 (2010), 1155–1158. DOI 10.1016/j.crma.2010.10.026 | MR 2738918 | Zbl 1204.42008
[11] Pogosyan N.B.: Universal Fourier series. Uspekhi Mat. Nauk 38 (1983), 185–186. MR 0693740 | Zbl 0525.42003
[12] Rudin W.: Real and Complex Analysis. McGraw-Hill Book Co., New York, 1987. MR 0924157 | Zbl 1038.00002
[13] Wintner A.: The theorem of Eneström and the extremal functions of Landau-Schur. Math. Scand. 5 (1957), 236–240. MR 0098192 | Zbl 0081.07103
[14] Zygmund A.: Trigonometric Series. Vol. I, II. Cambridge University Press, Cambridge, 2002. MR 1963498
Partner of
EuDML logo