标题： 存在违反微分同胚的非动力学背景场时的宇宙学 显示英文标题

标题： Cosmology in the presence of diffeomorphism-violating, nondynamical background fields

摘要： 我们研究了微分同胚破缺现象，这种破缺由引力标准模型扩展（SME）中的非动力学背景场参数化，并探讨了它对宇宙时间演化的影响。 我们的目标是识别出那些在没有奇异物质和辐射形式存在的背景下，仍能导致加速膨胀阶段的背景场构型。 尽管我们的方法产生了一组限制性条件，但我们还是找到了表现出这一性质或其他有趣行为的构型。 我们这篇文章的研究成果——这是最早将SME应用于宇宙学背景下的研究之一——为我们提供了初步的技术理解，即如何将背景场纳入宇宙学演化方程，并且可能产生的现象学影响是什么。 显示英文摘要

摘要： We consider diffeomorphism violation, which is parameterized by nondynamical background fields of the gravitational Standard-Model Extension (SME), and study its effects on the time evolution of the Universe. Our goal is to identify background field configurations that imply stages of accelerated expansion without exotic forms of matter and radiation present. Although our approach gives rise to a set of restrictive conditions, configurations are encountered that exhibit this property or show other interesting behaviors. The findings of our article, which is among the first to apply the SME to a cosmological setting, provide an initial understanding of how to technically incorporate background fields into the cosmological evolution equations and what their phenomenological impact may be.