We study long-range percolation on the hierarchical lattice of order N,
where any edge of length k is present with probability
pk=1−exp(−β−kα), independently of all other edges. For fixed
β, we show that the critical value αc(β) is non-trivial if
and only if N<β<N2. Furthermore, we show uniqueness of the infinite
component and continuity of the percolation probability and of
αc(β) as a function of β. This means that the phase diagram
of this model is well understood.Comment: 24 page