The improper infinite derivatives of Takagi's nowhere-differentiable function

被引:18
作者
Allaart, Pieter C. [1 ]
Kawamura, Kiko [1 ]
机构
[1] Univ N Texas, Dept Math, Denton, TX 76203 USA
关键词
Takagi's function; Nowhere-differentiable function; Improper derivative; Modulus of continuity;
D O I
10.1016/j.jmaa.2010.06.059
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Let T be Takagi's continuous but nowhere-differentiable function. Using a representation in terms of Rademacher series due to N. Kono [Acta Math. Hungar. 49 (1987) 315-324], we give a complete characterization of those points where T has a left-sided, right-sided, or two-sided infinite derivative. This characterization is illustrated by several examples. A consequence of the main result is that the sets of points where T'(x) = +/-infinity have Hausdorff dimension one. As a byproduct of the method of proof, some exact results concerning the modulus of continuity of T are also obtained. (C) 2010 Elsevier Inc. All rights reserved.
引用
收藏
页码:656 / 665
页数:10
相关论文
共 5 条
[1]  
Begle E. G., 1936, Amer. Math. Monthly, V43, P294
[2]  
Falconer K., 2003, FRACTAL GEOMETRY MAT, DOI DOI 10.1002/0470013850
[3]  
KONO N, 1987, ACTA MATH HUNG, V49, P315
[4]  
Kruppel M., 2007, ROSTOCK MATH K, V62, P41
[5]  
Takagi T., 1903, P PHYS-MATH SOC JPN, V1, P176