is the effective Rabi splitting; equivalent definitions can be made for the creation operators. It is worth noting that there is no free lunch: the superradiantly enhanced VSC with the bright mode occurs at the expense of the creation of a macroscopic number of dark modes that-under the context of this model-do not mix with light (inhomogeneous broadening results in small but experimentally observable light-like character for these modes ). This effect is negligible for the phenomena considered in this work given that the density of molecular excitations is much larger than that of the photon modes.)