Optimal uniform approximation of Lévy processes on Banach spaces with finite variation processes (1808.08373v3)

Abstract: For a general c`adl`ag L\'evy process on a separable Banach space $V$ we estimate values of $\inf_{Y\in{\cal A}X} \mathbb{E}\left{ \psi\left( \Vert X - Y \Vert\infty\right) + \mathrm{TV}(Y[0,T]) \right}$, where ${\cal A}_X$ is the family of processes on $V$ adapted to the natural filtration of $X$, $\psi$ has polynomial growth and TV$(Y[0,T])$ denotes the total variation of the process $Y$ on the interval $[0,T]$. Next, we apply obtained estimates in three specific cases: a Brownian motion with drift on $\mathbb{R}$, a standard Brownian motion on $\mathbb{R}^d$ and a symmetric $\alpha$-stable process ($\alpha\in(1,2)$) on $\mathbb{R}$.