2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/29191An effective Hamiltonian for spinless electrons in the lowest Landau level (LLL) close to half filling is derived. As opposed to the treatment in standard Chern-Simons theories (CS) we first project to the LLL and only then apply a CS-transformation on the Hamiltonian. The transformed field operators act in the lowest Landau level only {\it and} have fermionic commutation relations for small wavenumbers ignoring gauge field fluctuations. When acting on the Hamiltonian at half filling the {\it gauge transformation removes the monopole term in the interaction and does not eliminate the magnetic field.4 pagesMesoscale and Nanoscale Physicstext