# Quantization of unimodular gravity and the cosmological constant problems

@article{Smolin2009QuantizationOU, title={Quantization of unimodular gravity and the cosmological constant problems}, author={Lee Smolin}, journal={Physical Review D}, year={2009}, volume={80}, pages={084003} }

A quantization of unimodular gravity is described, which results in a quantum effective action which is also unimodular, ie a function of a metric with fixed determinant. A consequence is that contributions to the energy-momentum tensor of the form of g{sub ab}C, where C is a spacetime constant, whether classical or quantum, are not sources of curvature in the equations of motion derived from the quantum effective action. This solves the first cosmological constant problem, which is suppressing…

## 151 Citations

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