论文标题
我们因果宇宙的大小
The size of our causal Universe
论文作者
论文摘要
有限年龄的宇宙也具有有限的因果量表。较大的尺度不会影响我们的本地测量或建模，但是遥远的位置可能具有不同的宇宙学参数。我们的因果宇宙的大小取决于通货膨胀的细节，通常被认为比当今可观察到的宇宙大。为了考虑因果关系，我们提出了一种新的边界条件，可以通过固定宇宙常数（重力的自由几何参数）来实现。这迫使取消真空能量以宇宙常数。结果，所测得的宇宙加速度无法通过简单的宇宙恒定或恒定真空能来解释。我们需要一些其他奇特的属性，例如存在不断发展的深色能量（DE），并进行了微调，这是当今暗物质的两倍。我们在这里表明，假设因果量表小于当今可观察到的宇宙，我们可以改为解释没有DE（或修改性重力）的宇宙加速度。这样的量表对应于z = 1和60度的一半天空，在z = 1100时，这与CMB中观察到的相关性异常相一致。然后可以将宇宙加速度迟到，然后被解释为原始通货膨胀的吸烟枪。
A Universe with finite age also has a finite causal scale. Larger scales can not affect our local measurements or modeling, but far away locations could have different cosmological parameters. The size of our causal Universe depends on the details of inflation and is usually assumed to be larger than our observable Universe today. To account for causality, we propose a new boundary condition, that can be fulfill by fixing the cosmological constant (a free geometric parameter of gravity). This forces a cancellation of vacuum energy with the cosmological constant. As a consequence, the measured cosmic acceleration can not be explained by a simple cosmological constant or constant vacuum energy. We need some additional odd properties such as the existence of evolving dark energy (DE) with energy-density fine tuned to be twice that of dark matter today. We show here that we can instead explain cosmic acceleration without DE (or modified gravity) assuming that the causal scale is smaller than the observable Universe today. Such scale corresponds to half the sky at z=1 and 60 degrees at z=1100, which is consistent with the anomalous lack of correlations observed in the CMB. Late time cosmic acceleration could then be interpreted as the smoking gun of primordial Inflation.
