标题： 宇宙学中的标准模型之外（法语） 显示英文标题

标题： Beyond standard models in cosmology (In French)

摘要： 目前基本相互作用的描述基于两个标准模型理论。电磁相互作用和核相互作用通过粒子物理的标准模型，在量子层次上用规范理论以及希格斯机制引起的自发对称性破缺来描述。另一方面，引力相互作用则由广义相对论描述，该理论以经典水平上的时空动力学为基础。尽管这些模型在太阳系实验中被精确验证，但它们在普朗克尺度和宇宙尺度上存在若干理论缺陷，并缺乏预测能力；因此不再被视为基础理论。 由于宇宙学现象涉及这两种极端尺度，所以它是检验超越标准模型理论的一个很好的实验室。 本论文的第一部分关注宇宙弦，这是大统一理论在早期宇宙中自发对称性破缺时形成的拓扑缺陷。我特别展示了如何在考虑粒子物理模型完整结构的基础上研究这些缺陷，超越了用简化玩具模型进行的标准描述。 第二部分致力于构建和探讨与伽利略模型相关的各种修改引力理论，伽利略模型试图尤其解释暗能量现象。 显示英文摘要

摘要： The current description of fundamental interactions is based on two theories with the status of standard models. The electromagnetic and nuclear interactions are described at a quantum level by the Standard Model of particle physics, using tools like gauge theories and spontaneous symmetry breaking by the Higgs mechanism. The gravitational interaction is described on the other hand by general relativity, based on a dynamical description of space-time at a classical level. Although these models are verified to high precision in the solar system experiments, they suffer from several theoretical weaknesses and a lack of predictive power at the Planck scale as well as at cosmological scales; they are thus not viewed anymore as fundamental theories. As its phenomenology involves both these extreme scales, cosmology is then a good laboratory to probe theories going beyond these standard models. The first part of this thesis focus on cosmic strings, topological defects forming during the spontaneous symmetry breaking of grand unified theories in the early universe. I show especially how to study these defects while taking into account the complete structure of the particles physics models leading to their formation, going beyond the standard descriptions in terms of simplified toy-models. The second part is devoted to the construction and the examination of different theories of modified gravity related to the Galileon model, a model which tries in particular to explain the dark energy phenomenology.