The subdominant curvaton
- Physics Department, University of Helsinki, FIN-00014 Helsinki (Finland)
- Institute for Theoretical Physics, University of Heidelberg, 69120 Heidelberg (Germany)
- Helsinki Institute of Physics, University of Helsinki, FIN-00014 Helsinki (Finland)
- Department of Physics, Saga University, Saga 840-8502 (Japan)
We present a systematic study of the amplitude of the primordial perturbation in curvaton models with self-interactions, treating both renormalizable and non-renormalizable interactions. In particular, we consider the possibility that the curvaton energy density is subdominant at the time of the curvaton decay. We find that large regions in the parameter space give rise to the observed amplitude of primordial perturbation even for non-renormalizable curvaton potentials, for which the curvaton energy density dilutes fast. At the time of its decay, the curvaton energy density may typically be subdominant by a relative factor of 10{sup −3} and still produce the observed perturbation. Field dynamics turns out to be highly non-trivial, and for non-renormalizable potentials and certain regions of the parameter space we observe a non-monotonous relation between the final curvature perturbation and the initial curvaton value. In those cases, the time evolution of the primordial perturbation also displays an oscillatory behaviour before the curvaton decay.
- OSTI ID:
- 22273084
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 11 Vol. 2009; ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Curvaton dynamics revisited
Non-gaussianity with Lagrange multiplier field in the curvaton scenario