Verdaguer Oms, Enric, 1950-Mozota Frauca, Àlvaro2015-10-222015-10-222015-06https://hdl.handle.net/2445/67405Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Any: 2015, Tutor: Enric VerdaguerThe purpose of this paper is to study the homogeneous backreaction of non-zero mass conformally coupled scalar fields on a cosmological background, including at spacetime, at one-loop order. For this study, the semiclassical Friedmann equation is solved using a method called order reduction. For a nearly at background we get a scale factor that evolves to a stationary scale factor depending on the initial quantum state. We also prove that a de Sitter scale factor is also a mathematical solution of the semiclassical Friedmann equation, and we argue this is a runaway type solution.5 p.application/pdfengcc-by-nc-nd (c) Mozota Frauca, 2015http://creativecommons.org/licenses/by-nc-nd/3.0/es/CosmogoniaRelativitat (Física)Treballs de fi de grauCosmogonyRelativity (Physics)Bachelor's thesesinfo:eu-repo/semantics/bachelorThesisinfo:eu-repo/semantics/openAccess