Theory and simulations of super-critical black hole accretion flows

In this talk I will summarize the theory and most recent developments in numerical simulations of super-Eddington black hole accretion flows. I will discuss how different they are from the standard thin accretion disks, what their radiative and kinetic efficiencies are, what they look like if observed from infinity, and, finally, what we can learn from studying diffused nebulae surrounding some of the observed ultra-luminous X-ray sources.