论文标题
煎饼而不是瑞士奶酪
Pancakes as opposed to Swiss Cheese
论文作者
论文摘要
We examine a novel class of toy models of cosmological inhomogeneities by smoothly matching along a suitable hypersurface an arbitrary number of sections of "quasi flat" inhomogeous and anisotropic Szekeres-II models to sections of any spatially flat cosmology that can be described by the Robertson-Waker metric (including de Sitter, anti de Sitter and Minkowski spacetimes).由此产生的“煎饼”模型是与文献中发现的众所周知的球形“瑞士奶酪”模型的准燃料类似物。 Since Szekeres-II models can be, in general, compatible with a wide range of sources (dissipative fluids, mixtures of non-comoving fluids, mixtures of fluids with scalar or magnetic fields or gravitational waves), the pancake configurations we present allow for a description of a wide collection of localized sources embedded in a Robertson-Waker geometry.我们提供了与Einstein de Sitter相匹配的Szekeres-II区域任意数量的Szekeres-II区域的各种简单示例（它们的尘埃和能量通量被解释为特殊速度的领域），$λ$ CDM和De Sitter背景。我们还证明，在上面讨论的匹配定义的背景下，Szekeres-II区域可以被严格视为“精确”扰动。我们认为，这些模型对于测试平均和反应以及不均匀性对宇宙进化和观察的影响很有用。
We examine a novel class of toy models of cosmological inhomogeneities by smoothly matching along a suitable hypersurface an arbitrary number of sections of "quasi flat" inhomogeous and anisotropic Szekeres-II models to sections of any spatially flat cosmology that can be described by the Robertson-Waker metric (including de Sitter, anti de Sitter and Minkowski spacetimes). The resulting "pancake" models are quasi-flat analogues to the well known spherical "Swiss-cheese" models found in the literature. Since Szekeres-II models can be, in general, compatible with a wide range of sources (dissipative fluids, mixtures of non-comoving fluids, mixtures of fluids with scalar or magnetic fields or gravitational waves), the pancake configurations we present allow for a description of a wide collection of localized sources embedded in a Robertson-Waker geometry. We provide various simple examples of arbitrary numbers of Szekeres-II regions (whose sources are comoving dust and energy flux interpreted as a field of peculiar velocities) matched with Einstein de Sitter, $Λ$CDM and de Sitter backgrounds. We also prove that the Szekeres-II regions can be rigorously regarded as "exact" perturbations on a background defined by the matching discussed above. We believe that these models can be useful to test ideas on averaging and backreaction and on the effect of inhomogeneities on cosmic evolution and observations.
