Gravitational Waves and Energy-Momentum Quanta

The notion of energy-momentum in any relativistic description of gravitation is a subtle one and requires careful analysis in any cogent attempt to quantize the gravitational field. By embedding Einstein's original formulation of General Relativity into a broader context it will be show that a dynamic covariant description of purely gravitational stress-energy emerges naturally from a variational principle. A new tensor will be constructed (from a contraction of the Bel tensor with a symmetric covariant second degree tensor) that has a form analogous to the stress-energy tensor of the Maxwell field in an arbitrary space-time. For plane-fronted gravitational waves, helicity-2 polarised (graviton) states can be identified carrying non-zero energy and momentum.

The content of this talk will survey conventional wisdom on pure gravitational stress-energy, offer comments on the need for a tensorial formulation and construct a model in which such a formulation can be achieved. Some implications for the nature of gravitational quanta will be deduced from this model.

The talk will be based on published work by T Dereli and R W Tucker.