发表机构
College of Physics, Guizhou University（贵州大学物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分析范德瓦尔斯黑洞的光子环，利用EHT观测约束参数，发现其与M87*和Sgr A*观测高度一致，并能区分于史瓦西黑洞，为从观测推导黑洞微观物理提供新途径。
AI 中文摘要
范德瓦尔斯黑洞是反德西特（AdS）时空中的一种非克尔模型，表现出特征性的热力学相变。该模型中诸如黑洞分子体积$b$和压强$P$等参数的物理有效性是否可行，仍需观测验证。作为强引力场的灵敏探针，黑洞光子环直接携带时空几何信息，使其成为模型检验的理想对象。根据该黑洞对应的时空度规，本研究获得了光子的零测地线方程和守恒量，通过有效势分析确定了光子球条件和半径，研究了光子环的分类和辐射特性，并利用事件视界望远镜（EHT）的测量结果对参数施加约束并模拟光学外观。结果表明，分子体积参数$b$显著调节光子球半径、光子环结构和光度。在特定区间内，该模型与M87*和Sgr A*的EHT测量结果高度一致。该区间不仅满足能量条件（弱、强和主导），而且对应于稳定的范德瓦尔斯型相变区域。此外，光子环可以区分范德瓦尔斯黑洞和史瓦西黑洞：由于小黑洞-大黑洞（SBH-LBH）相变和微观结构的不连续性，范德瓦尔斯黑洞的光子环对参数$b$特别敏感，而史瓦西黑洞缺乏这些特征。这项工作利用光子环探测黑洞分子模型，将其微观结构、时空几何和观测特征联系起来，为从观测中推导黑洞微观物理提供了新途径。
英文摘要
The Van der Waals black hole (BH) is a non-Kerr model in Anti-de Sitter (AdS) spacetime that exhibits characteristic thermodynamic phase transitions. Whether the physical validity of parameters such as the BH molecular volume $b$ and pressure $P$ is feasible still requires observational verification. As a sensitive probe of strong gravitational fields, the BH photon ring directly carries spacetime geometric information, making it an ideal object for model testing. In accordance with the spacetime metric associated with this BH, this study obtains the null geodesic equations for photons and conserved quantities, determines the photon sphere conditions and radii via effective potential analysis, investigates the photon ring classification and radiative properties, and employs measurements from the Event Horizon Telescope (EHT) to place constraints on parameters and simulate the optical appearance. The results show that the molecular volume parameter $b$ significantly regulates the radius of the photon sphere radius, photon ring structure, and the luminosity. Within a specific interval, the model exhibits a high degree of agreement with the EHT measurements for M87* and Sgr A*. This interval not only satisfies the energy conditions (weak, strong, and dominant) but also corresponds to a stable Van der Waals-type phase transition region. Furthermore, the photon ring can distinguish between the Van der Waals BH and the Schwarzschild BH: due to the small-black-hole-large-black-hole (SBH-LBH) phase transition and microstructural discontinuities, the photon ring of the Van der Waals BH is particularly sensitive to the parameter $b$, whereas the Schwarzschild BH lacks these features. This work uses the photon ring to probe BH molecular models, linking its microstructure, spacetime geometry and observational signatures, and provides a new way to derive BH microphysics from observations.
Commentsv2: Corrected 13 numerical values in Table 1. Conclusions unchanged
