近日，瑞士欧洲核子研究中心的Matthew Dodelson与日内瓦大学的Cristoforo Iossa合作并取得一项新进展。他们对黑洞体锥奇点进行了研究。相关研究成果已于2024年7月5日在国际知名学术期刊《高能物理杂志》上发表。
该研究团队分析了AdS史瓦西黑洞背景波传播对偶热响应函数的奇点。研究人员导出了绕黑洞旋转的体测地线的主导奇点对偶的解析形式。值得注意的是，它表现出一个大于光速的边界群速度，其对偶是光子球处零测地线的角速度。奇点的强度由与近束缚光子轨道不稳定性有关的李亚普诺夫指数控制。从这个意义上说，体锥奇点可以被认为是编码双全息CFT中无处不在的黑洞光子球的普遍特征。
为了进行解析计算，研究人员将两点相关器表示为Regge极点上的无限和，然后使用WKB方法对该和进行计算。他们还对模糊相关器进行了数值计算，这一步骤尤为关键，因为它为他们提供了验证和支持其理论分析预测。他们评论了由弦效应和引力效应将黑洞体锥奇点分解为黑洞体锥“凸起”。最后得出的结论是，这些凸起是稳健的，可以作为桌面实验中模拟黑洞几何形状的目标。
据悉，局部算子的洛伦兹相关器在引力对偶理论中表现出惊人的奇异性。这些与涌现体几何中的零测地线有关。
附：英文原文
Title: Black hole bulk-cone singularities
Author: Dodelson, Matthew, Iossa, Cristoforo, Karlsson, Robin, Lupsasca, Alexandru, Zhiboedov, Alexander
Issue&Volume: 2024-07-05
Abstract: Lorentzian correlators of local operators exhibit surprising singularities in theories with gravity duals. These are associated with null geodesics in an emergent bulk geometry. We analyze singularities of the thermal response function dual to propagation of waves on the AdS Schwarzschild black hole background. We derive the analytic form of the leading singularity dual to a bulk geodesic that winds around the black hole. Remarkably, it exhibits a boundary group velocity larger than the speed of light, whose dual is the angular velocity of null geodesics at the photon sphere. The strength of the singularity is controlled by the classical Lyapunov exponent associated with the instability of nearly bound photon orbits. In this sense, the bulk-cone singularity can be identified as the universal feature that encodes the ubiquitous black hole photon sphere in a dual holographic CFT. To perform the computation analytically, we express the two-point correlator as an infinite sum over Regge poles, and then evaluate this sum using WKB methods. We also compute the smeared correlator numerically, which in particular allows us to check and support our analytic predictions. We comment on the resolution of black hole bulk-cone singularities by stringy and gravitational effects into black hole bulk-cone “bumps”. We conclude that these bumps are robust, and could serve as a target for simulations of black hole-like geometries in table-top experiments.
DOI: 10.1007/JHEP07(2024)046
Source: https://link.springer.com/article/10.1007/JHEP07(2024)046