论文标题
非 - 里曼尼亚宇宙学：剪切高音的作用
Non-Riemannian Cosmology: The role of Shear Hypermomentum
论文作者
论文摘要
我们认为在公制的植入设置中，通常会在一个完美的超流体设置中进行爱因斯坦 - 希尔伯特的动作。为了解码剪切高光的作用，我们在源上施加了消失的自旋和扩张零件，仅允许非变化的剪切。然后，我们考虑一个FLRW背景，并在存在剪切高光的存在下得出广义的弗里德曼方程。通过在剪切变量中提供一个状态方程式，我们研究了剪切对宇宙扩张的加速/减速作用的案例。特别是，我们看到剪切物提供了防止最初奇异性形成的可能性。我们还提供了剪切统治时代的一些精确解决方案，并讨论了剪切电流的物理意义。
We consider the usual Einstein-Hilbert action in a Metric-Affine setup and in the presence of a Perfect Hyperfluid. In order to decode the role of shear hypermomentum, we impose vanishing spin and dilation parts on the sources and allow only for non-vanishing shear. We then consider an FLRW background and derive the generalized Friedmann equations in the presence of shear hypermomentum. By providing one equation of state among the shear variables we study the cases for which shear has an accelerating/decelerating effect on Universe's expansion. In particular, we see that shear offers a possibility to prevent the initial singularity formation. We also provide some exact solutions in the shear dominated era and discuss the physical significance of the shear current.
