Universality in Quantum Hall systems: Coset construction of incompressiblestates

Incompressible Quantum Hall fluids (QHF's) can be described in the scaling limit by three-dimensional topological field theories. Thanks to the corres pondence between three-dimensional topological field theories and two dimen sional chiral conformal field theories (CCFT's), we propose to study QHF's from the point of view of CCFT's. We derive consistency conditions and stab ility criteria for those CCFT's that can be expected to describe a QHF. A g eneral algorithm is presented which uses simple currents to construct inter esting examples of such CCFT's. It generalizes the description of QHF's in terms of Quantum Hall lattices, Explicit examples, based on the coset const ruction, provide candidates for the description of Quantum Hall fluids with Hall conductivity sigma (H) = 1/2(e(2)/h), 1/4(e(2)/h), 3/5(e(2)/h), (e(2) /h),....