Bounds for heat transport in a porous layer

In this seminar I will talk about bounds on convective heat transport in a porous layer heated from below. The results I will present are established by C.R. Doering and P. Constantin and are derived using the background field variational method. The marginal stability concept will be introduced in order to derive rigorous limits on the time-averaged convective heat transport, i.e the Nusselt Number Nu, as a function of the Rayleigh number Ra.