Dynamical correlations in a half-filled Landau level

We formulate a self-consistent-field theory for the Chern-Simons fermions t o study the dynamical response function of the quantum Hall system at v=1/2 . Our scheme includes the effect of correlations beyond the random-phase ap proximation (RPA) employed to date for this system. We report results on th e density-response function, dynamic structure factor, the static structure factor, the longitudinal conductivity, and the interaction energy of the s ystem. The longitudinal conductivity calculated in this scheme shows linear dependence on the wave vector, like the experimentals results and the RPA, but the absolute values are higher than the experimental results. [S0163-1 829(99)12503-7].