Radiative constraints on brane quintessence

We investigate the constraints on quintessence arising from both renormalizable and non-renormalizable couplings where the 5D Planck mass is around the TeV scale. The quintessence field vacuum expectation value is typically of the order of the 4D Planck mass, while non-renormalizable operators are expected to be suppressed by the 5D Planck mass. Non-renormalizable operators are therefore important in computing the 4D effective quintessence potential. We then study the quantum corrections to the quintessence potential due to fermion and graviton loops. The tower of Kaluza-Klein modes competes with the TeV-scale cut-off, altering the graviton contribution to the vacuum polarization of quintessence. Nevertheless, we show that, as in four dimensions, the classical potential is stable to such radiative corrections.