15432 10.1140/epjc/s10052-026-15432-6 276 72 Islands in Kerr–Newman black holes Regular Article - Theoretical Physics Theoretical Physics 1 18 2026 2 12 2025 11 19 2026 2 10 2026 3 16 2026 3 16 National Natural Science Foundation of China No.12275166 No.12311540141 No.12547142 The Author(s) 2026 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . Funded by SCOAP3. 10052 86 86 3 3 Ming-Hui Yu yuminghui@shu.edu.cn Xian-Hui Ge gexh@shu.edu.cn https://ror.org/006teas31 grid.39436.3b 0000 0001 2323 5732 Department of Mathematics Shanghai University 99 Shangda Road Shanghai 200444 China https://ror.org/006teas31 grid.39436.3b 0000 0001 2323 5732 Department of Physics Shanghai University 99 Shangda Road Shanghai 200444 China Abstract We investigate the information paradox in the four-dimensional Kerr–Newman black hole by employing the recently proposed island paradigm. To accurately capture the behavior of entanglement entropy in Kerr–Newman spacetime, we analyze the form of quantum fields in the near-horizon limit. We demonstrate the field can be effectively described by a reduced two-dimensional field theory. Under the framework of this reduced two-dimensional theory, the entanglement entropy of radiation satisfies the Page curve. We also examine the impact of angular momentum and charges on the Page time and the scrambling time. A step further, we concentrate on analyzing the near extremal case. Resort to the Kerr/CFT correspondence, the near-horizon geometry of near extremal Kerr–Newman black holes can be taken account for a warped AdS geometry. In this scenario, the low-energy effective degrees of freedom are dominated by the Schwarzian zero mode, resulting in a one-loop correction to the partition function. The entanglement entropy is subsequently recalculated under the thermodynamic with corrections. Through explicit calculations, we finally find that the Page time and the scrambling time exhibits quantum delays. This strongly suggests that the near extremal geometry is governed by the Schwarzian dynamics, in which quantum fluctuations result in a reduced rate of information leakage. Moreover, we provide a rigorous discussion on the validity of the island formula and compute the entanglement entropy in Kerr–Newman AdS spacetime as a supplementary example. Our findings further substantiate information conservation and extend the island paradigm to the most general class of stationary spacetime.