Abstract
We investigate the linear cosmological perturbations of Hořava-Lifshitz gravity in a Friedmann-Robertson-Walker universe without any matter. Our results show that a new gauge-invariant dynamical scalar mode emerges, due to the gauge transformation under the “foliation-preserving” diffeomorphism and “projectability condition,” and it can produce a scale invariant power spectrum. In the infrared regime with , the dynamical scalar degree of freedom turns to be a nondynamical one at the linear order level.
- Received 13 May 2009
DOI:https://doi.org/10.1103/PhysRevD.80.041501
©2009 American Physical Society