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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.

An Explicit Euler-type Scheme for Lévy-driven SDEs with Superlinear and Time-Irregular Coefficients

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 -convergence rate arbitrarily close to 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 -convergence rate, arbitrarily close to . 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.
Paper Structure (11 sections, 13 theorems, 75 equations, 1 figure, 1 table)

This paper contains 11 sections, 13 theorems, 75 equations, 1 figure, 1 table.

Key Result

Proposition 2.1

If Assumptions asum:monotonocity to asum:continuity are met, the SDE eq:sde has a unique solution. . Further, if Assumptions asum:ic and asum:coercivity_p are also true, there exists a constant $K>0$, such that $\sup_{t\in[0,T]}E|x_t|^{q}\leq K.$

Figures (1)

  • Figure 1: $\mathcal{L}^p$-error of randomized tamed Euler scheme \ref{['eq:scm']} for SDE \ref{['eq:DWD']}.

Theorems & Definitions (25)

  • Remark 2.1
  • Proposition 2.1
  • Remark 2.2
  • Theorem 2.1
  • Corollary 2.1
  • Remark 2.3
  • Lemma 2.1
  • Lemma 2.2
  • Remark 2.4
  • Lemma 3.1
  • ...and 15 more