Instanton representation of Plebanski gravity: XVIII. Quantization and proposed resolution of the Kodama state

In this paper we have constructed a Hilbert space of states solving the initial value constraints of GR in the instanton representation of Plebanski gravity. The states are labelled by two free functions of position constructed from the eigenvalues of the CDJ matrix. This comprises the physical degrees of freedom of GR with a semiclassical limit corresponding to spacetimes of Petrov Type I, D and O. The Hamiltonian constraint in this representation is a hypergeometric differential equation on the states, for which we have provided a closed form solution. Additionally, we have clarified the role of the Kodama state within this Hilbert space structure, which provides a resolution to the issue of its normalizability raised by various authors.