Aronson-B\'enilan estimates for the porous medium equation under the   Ricci flow
  In this paper we study the porous medium equation (PME) coupled with the Ricci flow on complete manifolds with bounded nonnegative curvature operator. In particular, we derive Aronson-B\'enilan and Li-Yau-Hamilton type differential Harnack estimates for positive solutions to the PME, with a linear forcing term, under the Ricci flow. 
Huai-Dong Cao and Meng Zhu
math.DG math.AP