In one theory of this phenomenon, the Master constraint sometimes replaces an infinite number of Hamiltonian constraints. The action relevant in the study of this phenomenon includes the integral of the root of the determinant of a rank two tensor. Quantization of this gauge field leads to an infinite number of free parameters, which makes renormalization impossible. The main equations describing 
In one theory of this phenomenon, the Master constraint sometimes replaces an infinite number of Hamiltonian constraints. The action relevant in the study of this phenomenon includes the integral of the root of the determinant of a rank two tensor. Quantization of this gauge field leads to an infinite number of free parameters, which makes renormalization impossible. The main equations describing this field includes terms like the Ricci tensor and the metric times a cosmological constant. Being in this field is indistinguishable from constant acceleration according to the equivalence principle. For 10 points, name this force explained in general relativity as a result of the curving of spacetime near a mass.
In one theory of this phenomenon, the Master constraint sometimes replaces an infinite number of Hamiltonian constraints.
gravity [or the gravitational force; accept quantum gravity]