Table of Contents
Fetching ...

An Exponential Stochastic Runge-Kutta Type Method of Order up to 1.5 for SPDEs of Nemytskii-type

Claudine von Hallern, Ricarda Mißfeldt, Andreas Rößler

TL;DR

This work develops ERKM1.5, a derivative-free exponential stochastic Runge-Kutta method for semilinear SPDEs with Nemytskii-type pointwise multiplicative noise. The scheme achieves strong temporal convergence of order up to $\gamma\in[1,\tfrac{3}{2})$ while keeping computational cost near linear in the problem dimension, contrasting with derivative-heavy Taylor-type methods. The authors provide a rigorous framework, a uniform $L^p$ moment bound, and a complete convergence proof, supported by spectral Galerkin implementation and numerical experiments including explicit, linear multiplicative, and nonlinear examples. The results demonstrate that ERKM1.5 offers a practical and efficient avenue for high-order SPDE simulations with reduced derivative evaluation burden and favorable scaling in dimensionality.

Abstract

For the approximation of solutions for stochastic partial differential equations, numerical methods that obtain a high order of convergence and at the same time involve reasonable computational cost are of particular interest. We therefore propose a new numerical method of exponential stochastic Runge-Kutta type that allows for convergence with a temporal order of up to 3/2 and that can be combined with several spatial discretizations. The developed family of derivative-free schemes is tailored to stochastic partial differential equations of Nemytskii-type, i.e., with pointwise multiplicative noise operators. We prove the strong convergence of these schemes in the root mean-square sense and present some numerical examples that reveal the theoretical results.

An Exponential Stochastic Runge-Kutta Type Method of Order up to 1.5 for SPDEs of Nemytskii-type

TL;DR

This work develops ERKM1.5, a derivative-free exponential stochastic Runge-Kutta method for semilinear SPDEs with Nemytskii-type pointwise multiplicative noise. The scheme achieves strong temporal convergence of order up to while keeping computational cost near linear in the problem dimension, contrasting with derivative-heavy Taylor-type methods. The authors provide a rigorous framework, a uniform moment bound, and a complete convergence proof, supported by spectral Galerkin implementation and numerical experiments including explicit, linear multiplicative, and nonlinear examples. The results demonstrate that ERKM1.5 offers a practical and efficient avenue for high-order SPDE simulations with reduced derivative evaluation burden and favorable scaling in dimensionality.

Abstract

For the approximation of solutions for stochastic partial differential equations, numerical methods that obtain a high order of convergence and at the same time involve reasonable computational cost are of particular interest. We therefore propose a new numerical method of exponential stochastic Runge-Kutta type that allows for convergence with a temporal order of up to 3/2 and that can be combined with several spatial discretizations. The developed family of derivative-free schemes is tailored to stochastic partial differential equations of Nemytskii-type, i.e., with pointwise multiplicative noise operators. We prove the strong convergence of these schemes in the root mean-square sense and present some numerical examples that reveal the theoretical results.

Paper Structure

This paper contains 20 sections, 6 theorems, 104 equations, 3 figures, 1 table.

Key Result

Proposition 2.1

Let some arbitrary coefficients ${c_1}, {c_2}, {c_3}, {c_4}, {c_5}, {c_6}, {c_7} \in \mathbb{R} \setminus \{0\}$ be given, let $p \geq 2$ and assume that for some constants $\gamma\in[1,\frac{3}{2})$, $\alpha \in(\gamma-1,\gamma]$, $\beta \in (\gamma -\tfrac{1}{2}, \gamma]$, $\delta \in (\gamma-1, \beta]$, $\theta = \max \{ \gamma-\alpha, \gamma-\tfrac{1}{2}, 2(\gamma-\beta), 2(\gamma-\delta-\

Figures (3)

  • Figure 1: $L^2(\Omega,H)$-error at time $T=1$ versus number of time steps in $\log$-$\log$-scale for $M = 2^l$, $l\in\{2,3,\cdots,16\}$, for Example 1 in Section \ref{['Sec:ExactSolution']}.
  • Figure 2: $L^2(\Omega,H)$-error at $T=1$ versus number of time steps for $M = 2^l$, $l\in\{2,3,\cdots,14\}$ for Example 2 in Section \ref{['Sec:Example2']}.
  • Figure 3: $L^2(\Omega,H)$-error at $T=1$ versus number of time steps $M = 2^l$, $l\in\{2,3,\cdots,14\}$ for Example 3 in Section \ref{['Sec:Example3']}.

Theorems & Definitions (13)

  • Proposition 2.1
  • Theorem 2.2
  • Lemma 3.1
  • Remark 3.1
  • proof : Proof of Proposition \ref{['Prop:Bounds']}
  • proof : Proof of Theorem \ref{['Prop:Conv']}
  • Lemma 4.1
  • proof
  • Remark 4.1
  • Lemma 4.2
  • ...and 3 more