Bounds on charge and heat diffusivities in momentum dissipating   holography
  Inspired by a recently conjectured universal bound for thermo-electric diffusion constants in quantum critical, strongly coupled systems and relying on holographic analytical computations, we investigate the possibility of formulating Planckian bounds in different holographic models featuring momentum dissipation. For a simple massive gravity dilaton model at zero charge density we find robust linear in temperature resistivity and entropy density alongside a constant electric susceptibility. In addition we explicitly find that the sum of the thermo-electric diffusion constants is bounded. 
Andrea Amoretti, Alessandro Braggio, Nicodemo Magnoli, Daniele Musso
hep-th cond-mat.str-el