标题： 暴涨情景在非保守单模引力中的重建 显示英文标题

标题： Reconstruction of inflationary scenarios in non-conservative unimodular gravity

摘要： 单模引力是广义相对论的一种替代引力理论。 引力场方程是由爱因斯坦场方程的无迹版本给出的。 由于该理论的结构，单模引力允许一个扩散项，该扩散项表征了规范能量动量张量局部可能的非守恒性。 利用单模引力的这一特性，在本工作中，我们明确展示了如何构建一个可以与当前观测对比的暴胀阶段。 特别是，我们关注三个具有物理兴趣的不同暴胀场景。 这些场景中的一个重要元素是，加速膨胀仅由扩散项驱动，即没有暴胀子。 此外，在暴胀期间的原始谱是通过考虑与标准流体动力学物质相关的非均匀扰动（建模为单一超相对论性流体）来生成的。 对于每个场景，我们得到了原始谱的预测，并将其与最近的观测限制进行了对比。 显示英文摘要

摘要： Unimodular gravity is an alternative theory of gravity to general relativity. The gravitational field equations are given by the trace-free version of Einstein's field equations. Due to the structure of the theory, unimodular gravity admits a diffusion term that characterizes a possible non-conservation of the canonical energy-momentum tensor locally. Employing this feature of unimodular gravity, in the present work, we explicitly show how to construct an inflationary phase that can be contrasted with current observations. In particular, we focus on three different inflationary scenarios of physical interest. An important element in these scenarios is that the accelerated expansion is driven by the diffusion term exclusively, i.e. there is no inflaton. Furthermore, the primordial spectrum during inflation is generated by considering inhomogeneous perturbations associated to standard hydrodynamical matter (modeled as a single ultra-relativistic fluid). For each of the scenarios, we obtain the prediction for the primordial spectrum and contrast it with recent observational bounds.