Quantum Hall Effect In Bilayer Systems And The Noncommutative Plane: A   Toy Model Approach
  We have presented a quantum mechanical toy model for the study of Coulomb interactions in Quantum Hall (QH) system. Inclusion of Coulomb interaction is essential for the study of {\it{bilayer}} QH system and our model can simulate it, in the compound state, in a perturbative framework. We also show that in the noncommutative plane, the Coulomb interaction is modified at a higher order in the noncommutativity parameter $\theta$, and only if $\theta$ varies from layer to layer in the QH system. 
B. Basu and Subir Ghosh (Indian Statistical Institute)