We investigate the structure of two point functions for the QFT dual to an asymptotically Lorentzian AdS-wormhole. The bulk geometry is a solution of 5-dimensional second order Einstein Gauss Bonnet gravity and causally connects two asymptotically AdS space times. We revisit the GKPW prescription for computing two-point correlation functions for dual QFT operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values phi_0^\pm at each of the two asymptotic AdS regions, along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O^\pm and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom leaving at each boundary. The AdS_(1+1) geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterium to distinguish coupling from entanglement effects among the two set of degrees of freedom associated to each of the disconnected parts of the boundary.
We study probe scalar correlation functions in a Solodukhin wormhole corresponding to the non-rotating BTZ black hole, as a toy model for microstate geometries thereof. Using real-time holography, we obtain the retarded scalar correlator in the wormhole geometry and quantitatively compare it to the result of the hybrid WKB method for the same correlator. We also calculate an off-diagonal correlator $\sim\langle H L L H' \rangle$ involving two different (heavy) wormhole states.
The Goheer-Kleban-Susskind no-go theorem says that the symmetry of de Sitter space is incompatible with finite entropy. The meaning and consequences of the theorem are discussed in the light of recent developments in holography and gravitational path integrals. The relation between the GKS theorem, Boltzmann fluctuations, wormholes, and exponentially suppressed non-perturbative phenomena suggests: the classical symmetry between different static patches is broken; and that eternal de Sitter space -- if it exists at all -- is an ensemble average.
The recent paper 1809.01197 described how states of a holographic CFT can be approximated by states of a large collection of non-interacting BCFTs, such that the dual of the new system accurately approximates an arbitrarily large causal patch of the original geometry. In this paper, we first describe in more detail the geometries dual to such discrete BCFT systems, emphasizing that they are multi-boundary wormholes in which it is not possible to move causally between different asymptotic regions. By reintroducing couplings between the BCFTs in various ways, we show that the wormholes can be ma…
We study chaos in non-Lorentzian field theories, specifically Galilean and Carrollian conformal field theories in two dimensions. In a large central charge limit, we find that the Lyapunov exponent saturates the bound on chaos, conjectured originally for relativistic field theories. We recover the same Lyapunov exponent holographically by a shock-wave calculation in three-dimensional flat space cosmologies, providing further evidence for flat space holography.
As shown by Louko and Sorkin in 1995, topology change in Lorentzian signature involves spacetimes with singular points, which they called crotches. We modify their construction to obtain Lorentzian semiclassical wormholes in asymptotically AdS. These solutions are obtained by inserting crotches on known saddles, like the double-cone or multiple copies of the Lorentzian black hole. The crotches implement swap-identifications, and are classically located at an extremal surface. The resulting Lorentzian wormholes have an instanton action equal to their area, which is responsible for topological s…
Wormholes are intriguing classical solutions in General Relativity, that have fascinated theoretical physicists for decades. In recent years, especially in Holography, gravitationalWormhole geometries have found a new life in many theoretical ideas related to quantum aspects of gravity. These ideas primarily revolve around aspects of quantum entanglement and quantum information in (semi-classical) gravity. This is an introductory and pedagogical review of Wormholes and their recent applications in Gauge-Gravity duality and related ideas.
We find half-wormhole solutions in Jackiw-Teitelboim gravity by allowing the geometry to end on a spacetime D-brane with specific boundary conditions. This theory also contains a Euclidean wormhole which leads to a factorization problem. We propose that half-wormholes provide a gravitational picture for how factorization is restored and show that the Euclidean wormhole emerges from averaging over the boundary conditions. The wormhole is known to be dual to a Sachdev-Ye-Kitaev (SYK) model with random complex couplings. We find that the free energy of the half-wormhole is strikingly similar to t…
We study complex saddles of the Lorentzian path integral for 4D axion gravity and its dual description in terms of a 3-form flux, which include the Giddings-Strominger Euclidean wormhole. Transition amplitudes are computed using the Lorentzian path integral and with the help of Picard-Lefschetz theory. The number and nature of saddles is shown to qualitatively change in the presence of a bilocal operator that could arise, for example, as a result of considering higher-topology transitions. We also analyze the stability of the Giddings-Strominger wormhole in the 3-form picture, where we find th…
Holography and Renormalization in Lorentzian Signature
De Boer et.等人发现了（d+1）维渐近反de Sitter空间中超引力的Hamilton-Jacobi方程与对偶d维扰动共形场论的Callan-Symanzik方程之间的渐近等价性。我们在洛伦兹签名中讨论这种对应。根据Marolf的构造方法，我们构造了初态和终态之间的关联函数的生成函数的引力对偶，并找到了一类结果具有经典超引力极限的态。我们展示了如何在场论中描述指定二阶超引力运动方程的全套解的数据，尽管运行耦合的重整化群方程具有一阶性质：必须指定耦合和状态，后者影响Callan-Symanzik方程的解。
Wormholes are speculative structures linking disparate space-time points. Their geometry can be obtained by solving Einstein equations with tolerating the violation of null energy conditions. Recently, many researchers have studied different wormholes according to different criteria, and they achieved remarkable results. In this paper, we investigate a series of exact solutions of the static wormhole with smeared mass source geometry in modified $f(R)$ gravity theories. In fact, we consider the Lorentzian density distribution which is coming from a particle-like source. To be more specific, th…
We study a two-site Sachdev-Ye-Kitaev model with complex couplings and a weak inter-site interaction. At low temperatures, the system is dual to a Euclidean wormhole in Jackiw-Teitelboim gravity plus matter. Interestingly, the energy spectrum becomes real for sufficiently strong inter-site coupling despite the Hamiltonian being non-Hermitian. In gravity, this complex-to-real transition corresponds to a Euclidean-to-Lorentzian transition: a dynamical restoration of the gravitational SL(2,R) symmetry of the Lorentzian wormhole, broken to U(1) in the Euclidean wormhole. We show this by identifyin…
本文介绍了三阶Lovelock引力的$n$维Lorentz虫洞解。与爱因斯坦引力和高斯-邦尼引力的情况相反，我们发现虫洞的喉道半径$r_0$有一个下限，它取决于Lovelock系数、时空的维数和形函数。研究了喉道附近存在正常物质的条件，发现喉道附近的物质可以在$r_0 \leq r \leq r_{\max}$区域内是正常物质，其中$r_{\max}$依赖于Lovelock系数和形状函数.我们还发现负耦合常数的三阶Lovelock项扩大了正常物质区的半径，而负耦合常数的高阶Lovelock项扩大了正常物质区的半径。
我们研究了一个家庭的虫洞持续两个物质成分的演化：一个具有均匀和各向同性的属性$ρ(t)$和另一个非均匀和各向异性$ρ_{in}(t,r)$。这些不断发展的虫洞的膨胀率只由各向同性和均匀的物质成分$ρ(t)$决定。特别地，我们考虑了一族精确的双流体演化虫孔，它们在整个时空中以恒定速度膨胀，并满足主导和强能量条件。一般来说，对于各向同性流体$ρ(t)$和宇宙学常数$Λ$消失的情况，空间以恒定速度膨胀，而对于$ρ(t)=0$和$Λ\neq 0$，膨胀率由宇宙学常数决定。这里考虑的双流体演化虫洞是本作者在以前的工作中讨论的单流体模型的推广[Phys.\修订版本\ D { \bf 78}，104006（2008）;物理学修订版本\ D { \bf 79}，024005（2009）]。
We study the behavior of a specific Lorentzian wormhole family under gravitational perturbations. In earlier work [EPJC 80, 850 (2020)], we have proved the stability of a test scalar field in the background of the wormhole family, where the effective potential was that of a double barrier. Continuing with the stability analysis, here we focus on the more physically relevant scenario, that of axial gravitational perturbations. Interestingly, we find that the effective potential is a triple barrier for lower angular momentum modes. This raises important questions on the ringdown of the correspon…
Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；Universitat de Barcelona（巴塞罗那大学）；Inamori Research Institute for Science（稻盛科学研究所）
We consider a class of tripartite systems for which two $d$-dimensional QFTs are cross-coupled via a third $d+1$-dimensional "messenger" QFT. We analyse in detail the example of a pair of one-dimensional matrix quantum mechanics, coupled via a two-dimensional theory of the BF-type and compute its partition function and simple correlators. This construction is extendible in higher dimensions, using a Chern-Simons "messenger" theory. In all such examples, the exact partition function acquires a form, speculated to correspond to systems dual to Euclidean wormholes and the cross correlators are su…
Strong-to-Weak Spontaneous Symmetry Breaking from Wormholes in Holography
Kyoto University（京都大学）；The Hakubi Center for Advanced Research, Kyoto University（京都大学博慧中心）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；University of Tokyo（东京大学）；Kavli Institute for the Physics and Mathematics of the Universe, UTIAS, University of Tokyo（东京大学宇宙起源研究前沿中心卡弗里宇宙物理学与数学研究所）；Trans-Scale Quantum Science Institute, University of Tokyo（东京大学跨尺度量子科学研究所）；Center for Interdisciplinary Theoretical and Mathematical Sciences, RIKEN（理化学研究所跨学科理论与数学科学中心）
