AI 中文总结
研究黑洞周围Weyl耦合光子偏振相关观测特征，通过计算一系列α值下两个偏振的多种可观测量，用特定方案提取散射矩阵并交叉验证，发现后向信号受宇称保护且α = 0时为零是最清晰诊断。
AI 中文摘要
与外尔张量非最小耦合的光子在其两个线性偏振态中传播方式不同：黑洞周围的真空变成双折射介质。在史瓦西背景下，耦合系数α使两个偏振的光子球和临界碰撞参数分裂，产生双影和偏振相关的光子环；当α/M² = 0.75时，两个阴影边缘相距阴影半径的62%。我们计算了一系列α值下两个偏振的统一波动光学和几何光学可观测量：灰体因子、吸收截面、微分截面及其荣耀、后向双折射信号、阴影、光子环和零轨迹。用Riccati - Hankel匹配方案提取双偏振散射矩阵，并用三种独立的光线追踪器对几何光学链进行交叉验证。最清晰的诊断是后向信号：它受宇称保护，在α = 0时恒为零。
英文摘要
A photon coupled non-minimally to the Weyl tensor propagates differently in its two linear polarization states: the vacuum around a black hole becomes a birefringent medium. On a Schwarzschild background the coupling $α$ splits the photon sphere and the critical impact parameter of the two polarizations, producing a double shadow and a polarization-dependent photon ring; the two shadow edges separate by $62\%$ of the shadow radius at $α/M^2=0.75$. We compute a unified set of wave-optical and geometric-optical observables for both polarizations across a range of $α$: greybody factors, absorption cross sections, differential cross sections and their glories, a backward birefringence signal, shadows, photon rings, and null trajectories. The two-polarization scattering matrices are extracted with a Riccati--Hankel matching scheme that keeps the phase-sensitive observables reliable, and the geometric-optics chain is cross-validated with three independent ray tracers. The cleanest diagnostic is the backward signal: it is protected by parity and vanishes identically at $α=0$.Laboratory bounds on $α$ render these effects unobservable for supermassive black holes; order-unity couplings would require a black hole of primordial mass.
