We study the weak convergence order of two Euler-type discretizations of the log-Heston Model where we use symmetrization and absorption, respectively, to prevent the discretization of the underlying CIR process from becoming negative. If the Feller index $\nu$ of the CIR process satisfies $\nu>1$, we establish weak convergence order one, while for $\nu \leq 1$, we obtain weak convergence order $\nu-\epsilon$ for $\epsilon>0$ arbitrarily small. We illustrate our theoretical findings by several numerical examples.
翻译:我们研究了日志-赫斯顿模型两个Euler型离散点的衰弱趋同顺序,我们分别使用对称和吸收法,防止基础 CIR 过程的离散变得负。如果CIR 过程的Feller 指数 $\ nu$ 美元满足 $nu>1 $,我们就建立弱弱的趋同顺序,而对于$\ nu\leq 1 美元,我们获得弱弱的趋同顺序 $\ nu- epsilon$, 用于 $\ epsilon>0$ 任意小。我们用几个数字例子来说明我们的理论结论。