ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09262016-101843


Tipo di tesi
Tesi di laurea magistrale
Autore
CICCIARELLA, FRANCESCO
URN
etd-09262016-101843
Titolo
Universality Classes for models of Quintessence
Dipartimento
FISICA
Corso di studi
FISICA
Relatori
relatore Cella, Giancarlo
Parole chiave
  • universality classes
  • accelerated expansion
  • dark energy
  • beta-function
  • Cosmology
  • quintessence
Data inizio appello
17/10/2016
Consultabilità
Completa
Riassunto
In this work, we extend the formalism of universality classes, originally developed for models of inflation, to models of quintessence, a dynamical dark energy modelled as a scalar field. The presence of another component in the Universe, namely pressureless matter, forces us to distinguish between to phases: a transition phase where the contribution of the matter component is not negligible and an asymptotic phase of quintessence-dominance. We first focus on the latter, identify the possible universality classes which are compatible with the constraints; next, we turn our attention to the transition phase, expressing all the cosmological quantities in terms of typical quantities of the beta-function formalism. Then, plugging the form of the beta function of the identified universality classes, we plot the evolution of these quantities and compare their behavior with the observations and set constraints on the free parameters. The analysis is then repeated for models of quintessence non-minimally coupled to gravity.
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