Stochastic Differential Equation for a reflected Brownian motion

244 Views Asked by At

Is there a SDE for a (one-dimensional) reflected (at 0) drifted Brownian motion like $d X_t = \mu dt + \sigma d W_t$ for the normal Brownian motion?

1

There are 1 best solutions below

4
On BEST ANSWER

As discussed in this blog post, reflected Brownian motion satisfies the SDE $$ dX_t=\textrm{sign}(B_t)\ dB_t, $$ where $X_t=|B_t|$ is the reflected Brownian motion, and $$ \textrm{sign}(x)=\begin{cases}1,&x>0\\0,&x=0\\-1,&x<0.\end{cases} $$