Cosmological landscape from nothing: some like it hot
Cosmological landscape from nothing: some like it hot
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从无到有的宇宙景观：有些人喜欢炎热
DOI：
10.1088/1475-7516/2006/09/014
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发表时间：
2006
影响因子：
6.4
通讯作者：
A. Kamenshchik
中科院分区：
文献类型：
--
作者：
A. Barvinsky;A. Kamenshchik
我们提出了一个新的量子宇宙的图片，它的创建是通过密度矩阵定义的欧几里德路径积分描述。这产生了一个合奏的宇宙宇宙学的牺牲，在一个混合状态，这是动态优选的纯量子态的哈特尔-霍金型。后者被其瞬子的无穷大正作用动态地抑制，这是由宇宙学自举（热物质的自洽反反应）中量子场的共形异常产生的。这种自举方法解决了壳层上宇宙作用量的有界性问题，消除了欧几里得量子引力中小宇宙常数的红外灾难。宇宙学景观被证明局限于宇宙学常数Λmin≤Λ≤Λmax的有界范围。我们通过求解有效的欧几里德运动方程来分析反作用效应，从而排除了区域Λ<Λmin。上截止由真空能量的量子效应和由有效作用量的特殊鬼避免重整化介导的共形异常强制执行。他们建立了一个新的量子尺度Λmax，它由共形反常中的拓扑高斯-博内项的系数决定。这个尺度被认为是上限--无限序列的花环型瞬子的极限点，而花环型瞬子构成了完整的宇宙学景观。宇宙学常数范围对粒子现象学的依赖性暗示了弦真空景观的一种可能的动力学选择机制。
We suggest a novel picture of the quantum Universe—its creation is described through the density matrix defined by the Euclidean path integral. This yields an ensemble of universes—a cosmological landscape—in a mixed state which is shown to be dynamically preferable to the pure quantum state of the Hartle–Hawking type. The latter is dynamically suppressed by the infinitely large positive action of its instanton, generated by the conformal anomaly of quantum fields within the cosmological bootstrap (the self-consistent back-reaction of hot matter). This bootstrap suggests a solution to the problem of boundedness of the on-shell cosmological action and eliminates the infrared catastrophe of a small cosmological constant in Euclidean quantum gravity. The cosmological landscape turns out to be limited to a bounded range of the cosmological constant Λmin≤Λ≤Λmax. The domain Λ<Λmin is ruled out by the back-reaction effect which we analyse by solving effective Euclidean equations of motion. The upper cut-off is enforced by the quantum effects of vacuum energy and the conformal anomaly mediated by a special ghost-avoidance renormalization of the effective action. They establish a new quantum scale Λmax which is determined by the coefficient of the topological Gauss–Bonnet term in the conformal anomaly. This scale is realized as the upper bound—the limiting point of an infinite sequence of garland-type instantons which constitute the full cosmological landscape. The dependence of the cosmological constant range on particle phenomenology suggests a possible dynamical selection mechanism for the landscape of string vacua.