{ "id": "math/0601029", "version": "v2", "published": "2006-01-02T15:07:31.000Z", "updated": "2006-07-22T07:43:29.000Z", "title": "An Adaptive Euler-Maruyama Scheme For SDEs: Convergence and Stability", "authors": [ "H. Lamba", "J. C. Mattingly", "A. M. Stuart" ], "comment": "Corrected version. Cleaned up a number of proofs and replaced the incorrect proof in the appendex with a corrected one", "categories": [ "math.NA", "math.PR" ], "abstract": "The understanding of adaptive algorithms for SDEs is an open area where many issues related to both convergence and stability (long time behaviour) of algorithms are unresolved. This paper considers a very simple adaptive algorithm, based on controlling only the drift component of a time-step. Both convergence and stability are studied. The primary issue in the convergence analysis is that the adaptive method does not necessarily drive the time-steps to zero with the user-input tolerance. This possibility must be quantified and shown to have low probability. The primary issue in the stability analysis is ergodicity. It is assumed that the noise is non-degenerate, so that the diffusion process is elliptic, and the drift is assumed to satisfy a coercivity condition. The SDE is then geometrically ergodic (converges to statistical equilibrium exponentially quickly). If the drift is not linearly bounded then explicit fixed time-step approximations, such as the Euler-Maruyama scheme, may fail to be ergodic. In this work, it is shown that the simple adaptive time-stepping strategy cures this problem. In addition to proving ergodicity, an exponential moment bound is also proved, generalizing a result known to hold for the SDE itself.", "revisions": [ { "version": "v2", "updated": "2006-07-22T07:43:29.000Z" } ], "analyses": { "keywords": [ "adaptive euler-maruyama scheme", "convergence", "primary issue", "exponential moment bound", "explicit fixed time-step approximations" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......1029L" } } }