Curvature and entropy perturbations in generalized gravity
- Center for High-Energy Physics, Peking University, Beijing 100871 (China)
We investigate the cosmological perturbations in generalized gravity, where the Ricci scalar and a scalar field are nonminimally coupled via an arbitrary function f({phi},R). In the Friedmann-Lemaitre-Robertson-Walker background, by studying the linear perturbation theory, we separate the scalar-type perturbations into the curvature perturbation and the entropy perturbation, whose evolution equations are derived. Then we apply this framework to inflation. We consider the generalized slow-roll conditions and the quantization initial condition. Under these conditions, two special examples are studied analytically. One example is the case with no entropy perturbation. The other example is a model with the entropy perturbation large initially but decaying significantly after crossing the horizon.
- OSTI ID:
- 21296329
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 79, Issue 10; Other Information: DOI: 10.1103/PhysRevD.79.103525; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Theory of cosmological perturbations with cuscuton
Scalar field perturbations in HoĊava-Lifshitz cosmology