Please use this identifier to cite or link to this item:
http://hdl.handle.net/2445/180421
Title: | Bouncing universes and dark energy |
Author: | Sánchez Alcalde, Guillem |
Director/Tutor: | Solà Peracaula, Joan |
Keywords: | Energia fosca (Astronomia) Tensió de Hubble Treballs de fi de grau Dark energy (Astronomy) Hubble tension Bachelor's theses |
Issue Date: | Feb-2021 |
Abstract: | We consider the possibility of a universe whose dark energy (DE) is made out of a negative cosmological constant Λ and a dynamical component X, dubbed as ”cosmon”, which does not interact with Λ. Due to Λ < 0, the late-time accelerated expansion rate is caused by X. In this paper, the study of this framework has been performed by implementing a piece-wise function for the equation of state (EoS) parameter of the cosmon. This parametrization provides an analysis of the impact on the total DE behaviour when a transition from phantom-like to quintessence cosmon (or vice versa) takes place. It has been found that a stopping point in the Universe is displayed in the future when a transition of X from phantom-like to quintessence occurs. For such transition, the ratio of the DE density to matter density (ρD/ρm) is bounded, giving a possible solution to the cosmological coincidence problem. Furthermore, for a phantom-like cosmon at present, we can obtain values of the Hubble constant (H0) compatible with the ones acquired experimentally for cosmic microwave background data [1] and local data [2]. |
Note: | Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2021, Tutor: Joan Solà Peracaula |
URI: | http://hdl.handle.net/2445/180421 |
Appears in Collections: | Treballs Finals de Grau (TFG) - Física |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
SÁNCHEZ ALCALDE GUILLEM_3085501_assignsubmission_file_TFG-Sánchez-Alcalde-Guillem.pdf | 617.05 kB | Adobe PDF | View/Open |
This item is licensed under a Creative Commons License