The H？lder continuity of a class of 3-dimension ultraparabolic equations

We obtained the $C^{\a}$ continuity for weak solutions of a class of ultraparabolic equations with measurable coefficients of the form $${\ptl_t u}= \ptl_x(a(x,y,t)\ptl_x u)+b_0(x,y,t)\ptl_x u+b(x,y,t)\ptl_y u,$$ which generalized our recent results on KFP equations.