We show that a holographic description of four-dimensional asymptotically locally flat spacetimes is reached smoothly from the zero-cosmological-constant limit of anti-de Sitter holography. To this end, we use the derivative expansion of fluid/gravity correspondence. From the boundary perspective, the vanishing of the bulk cosmological constant appears as the zero velocity of light limit. This sets how Carrollian geometry emerges in flat holography. The new boundary data are a two-dimensional spatial surface, identified with the null infinity of the bulk Ricci-flat spacetime, accompanied with a Carrollian time and equipped with a Carrollian structure, plus the dynamical observables of a conformal Carrollian fluid. These are the energy, the viscous stress tensors and the heat currents, whereas the Carrollian geometry is gathered by a two-dimensional spatial metric, a frame connection and a scale factor. The reconstruction of Ricci-flat spacetimes from Carrollian boundary data is conducted with a flat derivative expansion, resummed in a closed form in Eddington-Finkelstein gauge under further integrability conditions inherited from the ancestor anti-de Sitter set-up. These conditions are hinged on a duality relationship among fluid friction tensors and Cotton-like geometric data. We illustrate these results in the case of conformal Carrollian perfect fluids and Robinson-Trautman viscous hydrodynamics. The former are dual to the asymptotically flat Kerr-Taub-NUT family, while the latter leads to the homonymous class of algebraically special Ricci-flat spacetimes.
Carrollian holography with agentic AI: Real mass is imaginary
Shanghai Institute for Mathematics and Interdisciplinary Sciences (SIMIS)（上海数学与交叉学科研究院）；Fudan Center for Mathematics and Interdisciplinary Study, Fudan University（复旦大学数学交叉研究中心）；Beijing Institute of Mathematical Sciences and Applications (BIMSA)（北京国际数学研究中心）
Spin-1 Bulk Local States in AdS/CFT and Carrollian Holography
University of Waterloo（滑铁卢大学）；Kyoto University（京都大学）；Hetao Institute of Mathematics and Interdisciplinary Sciences（河套数学与交叉科学研究院）；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）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所交叉理论与数学科学中心（iTHEMS））；Perimeter Institute for Theoretical Physics（理论物理珀塞尔研究所）
Carrollian-holographic Derivation of Gravitational Flux-Balance Laws
Centre de Physique Théorique, École polytechnique, Centre National de la Recherche Scientifique – Unité Mixte de Recherche 7644, Institut Polytechnique de Paris（巴黎综合理工学院理论物理中心）；International School for Advanced Studies (SISSA)（国际高等研究院）；Istituto Nazionale di Fisica Nucleare, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；Université de Mons（蒙斯大学）
Indian Institute of Technology Ropar（印度技术学院罗帕尔分校）；Beijing Institute of Mathematical Sciences and Applications（北京应用数学与交叉科学研究院）；Tata Institute of Fundamental Research（塔塔基础研究所）
Conformal Blocks in 2d Carrollian/Galilean CFTs and Excited State Entanglement Entropy
Center for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所引力物理与量子信息中心）；Yau Mathematical Sciences Center, Tsinghua University（清华大学丘成桐数学科学中心）；Department of Physics, Kyoto University（京都大学物理学系）；Perimeter Institute for Theoretical Physics（围场理论物理研究所）
Universal sectors of two-dimensional Carrollian CFTs
Institute for Theoretical Physics, TU Wien（维也纳工业大学理论物理研究所）；Indian Institute of Technology Kanpur（坎普尔印度理工学院）；International Solvay Institutes（国际索尔维研究所）；Okinawa Institute of Science and Technology Graduate University（冲绳科学技术大学院大学）；Quantum Technology Laboratories GmbH（量子技术实验室有限公司）；University of Edinburgh（爱丁堡大学）
Indian Institute of Technology Kanpur（坎普尔印度理工学院）；University of Victoria（维多利亚大学）；Chennai Mathematical Institute（金奈数学研究所）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；The Institute of Mathematical Sciences（数学科学研究所）
Gravitational Memory Beyond Null Infinity through Finite-Distance Carrollian Screens
Facultad de Ingeniería, Universidad San Sebastián（圣塞巴斯蒂安大学工程学院）；Department of Physics and Astronomy, University of Waterloo（滑铁卢大学物理与天文学系）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）；Departamento de Física, Universidad de Concepción（康塞普西翁大学物理系）
