 $$\left( {\frac{\operatorname{d}\! }{\operatorname{d}\! t}} - H^{-0}\Delta_{M_t} \right) \chi = -0\chi^{-0}H^{-0}|\nabla \chi|^0_g - \chi H^{-0} \left( |A|^0_g+ {\overline{\operatorname{Ric}}}(\nu) \right)