= Momentum-space propagator in a uniform force
{title2=$K_p=\theta(T)\delta(p-p'+\alpha T)e^{i(p^3-p'^3)/(6\alpha m\hbar)}$}
For potential $V(x)=\alpha x$, <momentum> follows a characteristic with $\dot p=-\alpha$. The retarded <quantum-mechanical propagator> translates its <momentum> argument and accumulates the kinetic <action> along that characteristic. Its apparent division by $\alpha$ is removable on the delta-function support; at zero <force> it becomes the free diagonal <momentum> kernel. <Fourier transform> gives the usual constant-force position kernel with a cubic-time <action> term.
Back to article page
