We consider numerically the dynamics of a flat anisotropic Universe in Einstein—Gauss—Bonnet gravity with positive Λ in dimensions 5 + 1 and 6 + 1. We identify three possible outcomes of the evolution, one singular and two nonsingular ones. The first nonsingular outcome is oscillatory. The second one is the known exponential solution. Its simplest version is the isotropic de Sitter solution. In Gauss—Bonnet cosmology there also exist anisotropic exponential solutions. When an exponential solution being a result of cosmological evolution has two different Hubble parameters, the evolution leads from an initially totally anisotropic stage to a warped product of two isotropic subspaces. We show that such a type of evolution is rather typical and possible even in the case where the de Sitter solution also exists.

中文翻译：

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由于爱因斯坦-高斯-邦尼引力的宇宙演化而分为两个各向同性的子空间

我们在数值上考虑了一个扁平的各向异性宇宙在爱因斯坦-高斯-贝内特引力中的正Λ，其维数为5 + 1和6 +1。我们确定了演化的三个可能结果，一个是奇异的，两个是非奇异的。第一个非奇异的结果是振荡的。第二个是已知的指数解。它最简单的版本是各向同性de Sitter解决方案。在高斯-邦尼特宇宙学中，还存在各向异性的指数解。当作为宇宙学演化结果的指数解具有两个不同的哈勃参数时，演化从最初的完全各向异性阶段过渡到两个各向同性子空间的翘曲积。我们表明，即使在也存在de Sitter解决方案的情况下，这种类型的演化也是相当典型的并且可能的。