Stochastic differential equations (SDEs) represent physical
phenomena
dominated by stochastic processes. Similar to deterministic ordinary
differential
equations (ODEs), various numerical schemes are proposed for SDEs.
Stability
analysis is significant for numerical SDEs as well, however a few results
have been
known. We have proposed the mean-square stability of numerical schemes for a
scalar SDE, that is, the numerical stability with respect to the mean-square
norm.
We studied it, however, only for scalar SDEs because of difficulty and
complexity in
SDE systems. Trying to make a breakthrough, we will consider a
2-dimensional linear
system with one multiplicative noise and give stability criteria under
several notions
of the matrix norm. This is a joint work with Yoshihiro Saito.