Ultraviolet complete inflation: looking at inflation from fundamental physics

Dias, Mafalda (2013) Ultraviolet complete inflation: looking at inflation from fundamental physics. Doctoral thesis (PhD), University of Sussex.

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To completely describe the inflationary era in the early universe is an extremely ambitious
task. The main reason is that its dynamics are highly sensitive to ultraviolet physics,
making the knowledge of inflation dependent on our ignorance of what is happening at
these energy scales. This is not necessarily a weakness of inflation as a paradigm; it is
ultimately its most interesting characteristic. Accepting this lack of control on the details
of inflationary dynamics brings observational cosmology and the search for an ultraviolet
complete theory of gravity together.
In this thesis, this duality is explored with the aim of making steps towards an efficient
way of studying inflation and its predictions and signatures. This challenge is twofold;
first, since fundamental theories are far from being able to explicitly determine the early
universe physics, the construction of approximate toy models is unavoidable. For this
reason, I identify the key issues for the building of a realistic inflation model, in particular
the delicate flatness of the inflaton potential, the strong possibility of multifield dynamics
and the necessity of a viable reheating, and in the light of these analyze how best to
approximate an ultraviolet complete inflation. For this analysis, two different classes of
case studies are presented: inflation in the brane picture and in a holography inspired
On the other hand, since any toy model of an ultraviolet complete inflation necessarily
presents a high level of complexity, the computation of predictions for observables is not
trivial. For this purpose, I develop numerical tools that manage to compute these parameters efficiently and with a high level of accuracy for a broad range of inflation classes with more than one active field. For each case study, I determine the impact of the inclusion of microphysics contributions in the resulting observational signatures and confront them with data.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy > QB0980 Cosmogony. Cosmology
Depositing User: Library Cataloguing
Date Deposited: 17 Apr 2013 08:43
Last Modified: 08 Sep 2015 14:41
URI: http://sro.sussex.ac.uk/id/eprint/44139

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