Where does gravity come from? A holographic RG story

Running a 2D quantum field theory through its renormalization group flow — essentially zooming out in energy scale — spontaneously generates a gravitational theory. Specifically, JT gravity, a much-studied 2D model of quantum black holes, pops out of the flow equations when the bulk geometry is pure Einstein-AdS₃. The dilaton field central to JT gravity turns out to be seeded by the radial lapse function of the bulk metric, giving a clean geometric origin for what was previously treated as a free ingredient.