Solà Peracaula, JoanBernárdez Gil, Guillermo2016-03-082016-03-082016-01https://hdl.handle.net/2445/96261Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2016, Tutor: Joan Solà PeracaulaThe possibility of a slow cosmic evolution of fundamental \constants" of Nature has been discussed for a long time without being consolidated; recently, however, more and more experiments are arising whose results seem to support this idea. Apart from that, in an expanding universe the vacuum energy density p is expected to be a time-evolving parameter rather than the rigid one proposed in the standard ACDM model; in fact, quantum feld theory in curved space time suggests a slow evolution determined by the expansion rate of the universe H. In this work, we will try to obtain and develop some cosmological models with such a a dynamical vacuum energy density, and at the same time we will check whether they can provide an explanation for the alleged slow time variation of the fundamental constants5 p.application/pdfengcc-by-nc-nd (c) Bernárdez, 2016http://creativecommons.org/licenses/by-nc-nd/3.0/es/Models astronòmicsCosmologiaTreballs de fi de grauConstants físiquesAstronomical modelsCosmologyBachelor's thesesPhysical constantsinfo:eu-repo/semantics/bachelorThesisinfo:eu-repo/semantics/openAccess