Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations

Details Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations

2010-06-28

arxiv.org/abs/1006.5321v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

PhD Thesis, Queen Mary, Univ of London, Supervisor: James E. Lidsey. (211 pages, 35 figures)

Scientific paper

Inflationary cosmology is the leading explanation of the very early universe. Many different models of inflation have been constructed which fit current observational data. In this work theoretical and numerical methods for constraining the parameter space of a wide class of such models are described. First, string-theoretic models with large non-Gaussian signatures are investigated. An upper bound is placed on the amplitude of primordial gravitational waves produced by ultra-violet Dirac-Born-Infeld inflation. In all but the most finely tuned cases, this bound is incompatible with a lower bound derived for inflationary models which exhibit a red spectrum and detectable non-Gaussianity. By analysing general non-canonical actions, a class of models is found which can evade the upper bound when the phase speed of perturbations is small. The multi-coincident brane scenario with a finite number of branes is one such model. For models with a potentially observable gravitational wave spectrum the number of coincident branes is shown to take only small values. The second method of constraining inflationary models is the numerical calculation of second order perturbations for a general class of single field models. The Klein-Gordon equation at second order, written in terms of scalar field variations only, is numerically solved. The slow roll version of the second order source term is used and the method is shown to be extendable to the full equation. This procedure allows the evolution of second order perturbations in general and the calculation of the non-Gaussianity parameter in cases where there is no analytical solution available.

Affiliated with

Also associated with

No associations

Rating

Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraining Inflationary Scenarios with Braneworld Models and Second Order Cosmological Perturbations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-616901