{ "id": "1806.05702", "version": "v1", "published": "2018-06-14T18:48:59.000Z", "updated": "2018-06-14T18:48:59.000Z", "title": "On (signed) Takagi-Landsberg functions: $p^{\\text{th}}$ variation, maximum, and modulus of continuity", "authors": [ "Yuliya Mishura", "Alexander Schied" ], "categories": [ "math.PR" ], "abstract": "We study a class $\\mathfrak X^H$ of signed Takagi-Landsberg functions with Hurst parameter $H\\in(0,1)$. We first show that the functions in $\\mathfrak X^H$ admit a linear $p^{\\text{th}}$ variation along the sequence of dyadic partitions of $[0,1]$, where $p=1/H$. The slope of the linear increase can be represented as the $p^{\\text{th}}$ absolute moment of the infinite Bernoulli convolution with parameter $2^{H-1}$. The existence of a continuous $p^{\\text{th}}$ variation enables the use of the functions in $\\mathfrak X^H$ as test integrators for higher-order pathwise It\\^o calculus. Our next results concern the maximum, the maximizers, and the modulus of continuity of the classical Takagi-Landsberg function for all $0