Cosmology on the Generalized Proca Theory

Abstract: This thesis employs the dynamical systems approach to explore two cosmological models: an anisotropic dark energy scenario in a Bianchi-I background and the Generalized SU(2) Proca (GSU2P) theory in a flat FLRW background. In the first case, a numerical framework is developed to analyze the interaction between a scalar tachyon field and a vector field, identifying parameter regions that allow anisotropic accelerated attractors. The second case examines the viability of GSU2P as a driver of inflation and late-time acceleration. Our analysis reveals fundamental limitations, including the absence of stable attractors and smooth cosmological transitions, ultimately ruling out the model as a complete description of the Universe's expansion. This work highlights the effectiveness of dynamical systems techniques in assessing alternative cosmological scenarios and underscores the need for refined theoretical frameworks aligned with observational constraints.