Soliton time delay
= Soliton time delay
{title2=$\Delta t=-\Delta x/v$}
If a labeled <soliton> approaches $x=vt+a_-$ before a collision and $x=vt+a_+$ afterwards, its spatial shift is $\Delta x=a_+-a_-$. For $v\ne0$, define its time delay at a fixed spatial point by $\Delta t=-\Delta x/v$. Thus a positive forward shift of a right-moving <soliton> is a negative time delay. For a stationary <soliton>, the spatial shift is well defined but this time-delay definition is not.