LaTeX, 10 pages, 2 figures, comparison of setting the problem and results with those of hep-th/0010232 is included, numerics is improved, new references are added
The path integration technique recently developed for the statistical sum of the microcanonical ensemble in cosmology is applied to the calculation of the one-loop preexponential factor in the cosmological model generated by a conformal field theory with a large number of quantum species -- the model of initial conditions possibly related to the resolution of the cosmological constant and landscape problems. The result is obtained for the family of background cosmological instantons with one oscillation of the FRW scale factor. The magnitude of the prefactor is analytically and numerically estimated for fields of various spins conformally coupled to gravity, which justifies the validity of semiclassical expansion for this family of cosmological instantons.
Time-dependent scalar fields provide a candidate explanation for the dark energy. For these to vary on cosmological time scales, the derivative of the scalar potential in Planck units should have roughly the same magnitude as the potential itself. We emphasize that scalars with this property are present in any four-dimensional gravitational effective theory with a known UV completion via holography, provided that the dual CFT has scalar operators with dimensions of order one. Cosmological solutions without time-dependent scalars are analogous to solutions dual to the vacuum states of such CFTs…
In this note, we explore the possibility that certain high-energy holographic CFT states correspond to black hole microstates with a geometrical behind-the-horizon region, modelled by a portion of a second asymptotic region terminating at an end-of-the-world (ETW) brane. We study the time-dependent physics of this behind-the-horizon region, whose ETW boundary geometry takes the form of a closed FRW spacetime. We show that in many cases, this behind-the-horizon physics can be probed directly by looking at the time dependence of entanglement entropy for sufficiently large spatial CFT subsystems.…
Quantum cosmology, inflationary brane-world creation and dS/CFT correspondence
在经典和量子水平上讨论了粘在两个d5 de Sitter体上的4d de Sitter（暴胀）边界的产生（考虑了膜QFT通过相应的迹反常诱导的有效作用）.量子效应使经典的de Sitter膜半径减小或产生新的半径更小的de Sitter膜。重要的是，膜CFT可以被选择为与5d de Sitter体之一对偶，使得de Sitter膜世界与dS/CFT对应的显式关系。这样，引力在膜上的局部化就被显示出来了。移动（含时）deSitter膜在d5 SdS BH被认为是。在特殊的坐标系中，膜方程类似于量子修正的FRW方程，并与SAdS BH体中的类似膜方程进行了比较。
We study the dynamical system approach of non minimally coupled scalar field to induced gravity on the brane in the framework of the AdS/CFT correspondence. In this context, we derive the modified Friedmann equation and the equation of motion. The dynamics of this model are studied by rewriting the cosmological field equations in the form of a system of autonomous differential equations. In particular, the analysis is considered by investigating an exponential potential and a monomial form of the non minimal coupling function. We show that, for sufficient conditions, a past de Sitter attractor…
We describe a class of holographic models that may describe the physics of certain four-dimensional big-bang / big-crunch cosmologies. The construction involves a pair of 3D Euclidean holographic CFTs each on a homogeneous and isotropic space $M$ coupled at either end of an interval ${\cal I}$ to a Euclidean 4D CFT on $M \times {\cal I}$ with many fewer local degrees of freedom. We argue that in some cases, when the size of $M$ is much greater than the length of ${\cal I}$, the theory flows to a gapped / confining three-dimensional field theory on $M$ in the infrared, and this is reflected in …
University of Cambridge（剑桥大学）；Okinawa Institute of Science and Technology（冲绳科学技术大学院大学）；Kavli Institute for Theoretical Physics, Santa Barbara（卡弗里理论物理研究所）；Laboratory for Theoretical Fundamental Physics, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院物理学院基础物理实验室）；School of Natural Sciences, Institute for Advanced Study（高等研究院自然科学院）
In the last two decades the Anti-de Sitter/Conformal Field Theory correspondence (AdS/CFT) has emerged as focal point of many research interests. In particular, it functions as a stepping stone to a still missing full quantum theory of gravity. In this context, a pivotal question is if and how cosmological physics can be studied using AdS/CFT. Motivated by string theory, braneworld cosmologies propose that our universe is a four-dimensional membrane embedded in a bulk five-dimensional AdS spacetime. We show how such a scenario can be microscopically realized in AdS/CFT using special field theo…
Standard cosmology from the brane cosmology with a localized matter
讨论了5D anti de Sitter Reissner-Nordstrom（AdSRN $_5$）时空中的膜宇宙学.具有张力$σ$的膜被定义为具有质量$M$和电荷$Q$的AdSRN $_5$空间的边缘。在这种情况下，我们从类弗里德曼方程中的$M$和$Q^2$中分别得到了CFT辐射项$(ρ_{CFT})$和带电尘埃$(-ρ^2_{cd})$。然而，该方程是不合理的，因为它包含带负号的$ρ_{cd}^2$ -项。从标准宇宙学的角度来看，这是非常规的。为了解决这个问题，我们引入了一个满足$P_{dm}=0$的局域尘埃物质。如果是$ρ_{dm}=\fr{\sqrt 3}{2}ρ_{cd}$，则不需要的$-ρ_{cd}^2$与$ρ_{dm}^2$抵消，从而恢复了具有CFT辐射和尘埃物质的标准Friedmann-Robertson-Walker宇宙。考虑到刚性问题，我们可以将$ρ_{csti}\sim Q^2$设置为负号。在这里，我们引入一个无质量标量，它扮演着一个刚性物质的角色与$P_{sca}=ρ_{sca}$取消$-ρ_{csti}$。然而，在这种情况下，我们发现了标准宇宙学和膜宇宙学的混合版本。
Certain closed-universe big-bang/big-crunch cosmological spacetimes may be obtained by analytic continuation from asymptotically AdS Euclidean wormholes, as emphasized by Maldacena and Maoz. We investigate how these Euclidean wormhole spacetimes and their associated cosmological physics might be described within the context of AdS/CFT. We point out that a holographic model for cosmology proposed recently in arXiv:1810.10601 can be understood as a specific example of this picture. Based on this example, we suggest key features that should be present in more general examples of this approach to …
We review the construction of holography for cosmologies with an emphasis on asymptotically de Sitter cosmologies. We do this by composition of the AdS/CFT correspondence and domain-wall/cosmology (DW/C) correspondence with the novel added benefit of keeping track of the DW/C marker $η$. This allows us to build explicitly the holographic dual of the DW/C correspondence. We then test this framework on a toy model: the GPPZ flow. We find the scalar one-point function for this flow to be invariant under the domain-wall/cosmology correspondence. Moreover, our construction seems to agree with previ…
Conformal field theory (CFT) dispersion relations reconstruct correlators in terms of their double discontinuity. When applied to the crossing equation, such dispersive transforms lead to sum rules that suppress the double-twist sector of the spectrum and enjoy positivity properties at large twist. In this paper, we construct dispersive CFT functionals for correlators of unequal scalar operators in position- and Mellin-space. We then evaluate these functionals in the Regge limit to construct mixed correlator holographic CFT functionals which probe scalar particle scattering in Anti-de Sitter s…
A baby universe from a large family: booklet cosmology states and quantum error correction
University of the Chinese Academy of Sciences（中国科学院大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Peng Huanwu Center for Fundamental Theory（彭桓武理论研究中心）
7D Randall-Sundrum cosmology, brane-bulk energy exchange and holography
我们讨论了7 D Randall-Sundrum（RS）引力系统的宇宙学意义和全息对偶理论。在7维重力场的一侧加入一般物质，我们研究了由膜-体能量交换参数的非零值所推断的宇宙演化。这种分析是实现详细的内部空间演化的特定假设，包括分析考虑和数值结果。对偶理论，然后构建，利用全息重整化过程。由此产生的重整化6D CFT是异常的，并耦合到6D重力加高阶修正。对膜进行了临界点分析。最后，我们勾勒出两个双重描述之间的比较。此外，我们推广的AdS/CFT对偶理论的非共形和相互作用的情况下，有关的能量交换参数的体积重力描述隐藏和可见部门之间的新的相互作用。
It was recently shown that the homogeneous and isotropic cosmology of a massless scalar field coupled to general relativity exhibits a new hidden conformal invariance under Mobius transformation of the proper time, additionally to the invariance under time-reparamterization. The resulting Noether charges form a $sl(2,\mathbb{R})$ Lie algebra, which encapsulates the whole kinematics and dynamics of the geometry. This allows to map FLRW cosmology onto conformal mechanics and formulate quantum cosmology in $\text{CFT}_1$ terms. Here, we show that this conformal structure is embedded in a larger $…
