Positivity-preserving truncated Euler–Maruyama method for generalised Ait-Sahalia-type interest model

Deng, Shounian and Fei, Chen and Fei, Weiyin and Mao, Xuerong (2023) Positivity-preserving truncated Euler–Maruyama method for generalised Ait-Sahalia-type interest model. BIT Numerical Mathematics, 63 (4). 59. ISSN 0006-3835 (https://doi.org/10.1007/s10543-023-01000-x)

[thumbnail of Deng-etal-BITNM-2023-Positivity-preserving-truncated-Euler-Maruyama-method-for-generalised-Ait-Sahalia-type-interest-model] Text. Filename: Deng-etal-BITNM-2023-Positivity-preserving-truncated-Euler-Maruyama-method-for-generalised-Ait-Sahalia-type-interest-model.pdf
Accepted Author Manuscript
Restricted to Repository staff only until 1 November 2024.
License: Strathprints license 1.0

Download (890kB) | Request a copy

Abstract

The well-known Ait-Sahalia-type interest model, arising in mathematical finance, has some typical features: polynomial drift that blows up at the origin, highly nonlinear diffusion, and positive solution. The known explicit numerical methods including truncated/tamed Euler–Maruyama (EM) applied to it do not preserve its positivity. The main interest of this work is to investigate the numerical conservation of positivity of the solution of generalised Ait-Sahalia-type model. By modifying the truncated EM method to generate positive sequences of numerical approximations, we obtain the rate of convergence of the numerical algorithm not only at time T but also over the time interval [0, T]. Numerical experiments confirm the theoretical results.