Testing the topological nature of the fractional quantum Hall edge

We carry out numerical diagonalization for much larger systems than before by restricting the fractional quantum Hall (FQH) edge excitations to a basis that is exact for a short-range interaction and very accurate for the Coulomb interaction. This enables us to perform substantial tests of the predicted universality of the edge physics. Our results provide compelling evidence that the behavior of the FQH edge is intrinsically nonuniversal, even in the absence of edge reconstruction, and therefore does not bear a sharp and unique relation to the bulk FQH state.