Primordial perturbations during a slow expansion
- College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)
Recently, it has been shown that a slow expansion, which is asymptotically a static state in infinite past and may be described as an evolution with {epsilon}<<-1, of early universe may lead to the generation of primordial perturbation responsible for the structure formation of observable universe. However, its feasibility depends on whether the growing mode of Bardeen potential before phase transition can be inherited by the constant mode of curvature perturbation after phase transition. In this paper, we phenomenally regard this slow expansion as that driven by multi-NEC (null energy condition) violating scalar fields. We calculate the curvature perturbation induced by the entropy perturbation before phase transition and find that the spectrum is naturally scale invariant with a slight red tilt. The result has an interesting similarity to that of slow roll inflation.
- OSTI ID:
- 21032428
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 76, Issue 8; Other Information: DOI: 10.1103/PhysRevD.76.083505; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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