The submartingale problem for a class of degenerate elliptic operators

Richard F. Bass, Alexander Lavrentiev

We consider the degenerate elliptic operator acting on $C^2$ functions on $[0,\infty {)}^d$: \[ L f(x)=\sum_{i=1}^d a_i(x) x_i^{α_i} \frac{\partial^2 f}{\partial x_i^2} (x) +\sum_{i=1…