An Explicit Euler-type Scheme for Lévy-driven SDEs with Superlinear and Time-Irregular Coefficients
Sani Biswas, Joaquin Fontbona
TL;DR
The paper addresses strong numerical approximation of Lévy-driven SDEs with superlinear and time-irregular drift (Carathéodory type). It introduces a randomized tamed Euler scheme that combines drift taming with randomized evaluation times to cope with time irregularity and jumps. The main theoretical contributions are a strong $L^2$-convergence rate arbitrarily close to $0.5$ under mild time-regularity assumptions, and an extension to Lévy-driven stochastic delay differential equations with Markovian switching, with explicit taming forms verified to satisfy the required conditions. Numerical experiments on Levy-driven double-well dynamics corroborate the theory and illustrate applicability to complex jump-diffusion models.
Abstract
This paper introduces a randomized tamed Euler scheme tailored for Lévy-driven stochastic differential equations (SDEs) with superlinear random coefficients and Carathéodory-type drift. Under assumptions that allow for time-irregular drifts while ensuring appropriate time-regularity of the diffusion and jump coefficients, the proposed scheme is shown to achieve the optimal strong $\mathcal{L}^2$-convergence rate, arbitrarily close to $0.5$. A crucial component of our methodology is the incorporation of drift randomization, which overcomes challenges due to low time-regularity, along with a taming technique to handle the superlinear state dependence. Our analysis moreover covers settings where the coefficients are random, providing for instance strong convergence of randomized tamed Euler schemes for Lévy-driven stochastic delay differential equations (SDDEs) with Markovian switching. To our knowledge, this is the first {work} that addresses the case of superlinear coefficients in the numerical analysis of Carathéodory-type SDEs and even for ordinary differential equations.
