Critical geometry of a thermal big bang
Critical geometry of a thermal big bang
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DOI：
10.1103/physrevd.94.101301
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发表时间：
2016-03
影响因子：
5
通讯作者：
N. Afshordi;J. Magueijo
中科院分区：
文献类型：
--
作者：
N. Afshordi;J. Magueijo
我们探索了包含两个非共形度量的标量张量理论的空间，并找到了指向“临界”宇宙学解的不连续点。由于物质和重力的最大传播速度不同，即使没有膨胀，宇宙波动也会在视界内开始，并且更自然地有一个热起源（因为从来没有真空统治）。临界模型对标量波动的谱指数作了明确的、非调谐的预测：${n}_{S}=0.96478(64)$。考虑到没有引力波产生，我们已经公布了目前最具预测性的模型。该模型具有简单的几何解释，即嵌入在$E{\ mathm {AdS}}_{2}\ifmmode\times\else\texttimes\fi{}{E}_{3}$ geometry中的探针3膜。
We explore the space of scalar-tensor theories containing two nonconformal metrics, and find a discontinuity pointing to a ``critical'' cosmological solution. Due to the different maximal speeds of propagation for matter and gravity, the cosmological fluctuations start off inside the horizon even without inflation, and will more naturally have a thermal origin (since there is never vacuum domination). The critical model makes an unambiguous, nontuned prediction for the spectral index of the scalar fluctuations: ${n}_{S}=0.96478(64)$. Considering also that no gravitational waves are produced, we have unveiled the most predictive model on offer. The model has a simple geometrical interpretation as a probe 3-brane embedded in an $E{\mathrm{AdS}}_{2}\ifmmode\times\else\texttimes\fi{}{E}_{3}$ geometry.