标题： 黑洞在腔内投射的光轨迹和热阴影 显示英文标题

标题： Light Trajectories and Thermal Shadows casted by Black Holes in a Cavity

摘要： 我们研究了腔内黑洞投射的阴影和光子环。 将观察者置于这种等温背景下，我们考察了腔体温度 T_{空腔}和电荷 Q 对相关光学特性的影响。 在通过改变 Q 研究视界半径的影响后，我们探讨了腔内黑洞阴影的热行为。 对于固定的电荷值，我们发现阴影半径 r_s 随着 T_{cav}的减小而增大。 通过改变该温度，我们讨论了相关的能量发射率。 之后，我们表明 r_s-T_{腔体}平面上的曲线与反德西特（AdS）黑洞的 G-T 曲线具有相似性。 然后，我们研究了腔内黑洞投射的光线轨迹。 我们进一步观察到，由于腔体效应，光线轨迹行为与非旋转黑洞的不同。 最后，我们提供了存在一个以光球半径和影响参数定义的普适比的证据。 具体而言，我们得到了一个光学比值\frac{b_{sp}}{r_{sp}} \sim \sqrt 3。 显示英文摘要

摘要： We explore the shadows and the photon rings casted by black holes in cavity. Placing the observer inside such an isothermal background, we examine the influence of the cavity temperature T_{cav} and the charge Q on the involved optical aspect. After studying the effect of the horizon radius by varying Q, we investigate the thermal behaviors of the black hole shadows in a cavity. For fixed charge values, we find that the shadow radius r_s increases by decreasing T_{cav}. Varying such a temperture, we discuss the associated energy emission rate. After that, we show that the curves in the r_s-T_{cav} plane share similarities with the G-T curves of the Anti de Sitter (AdS) black holes. Then, we study the trajectory of the light rays casted by black holes in a cavity. We further observe that the light trajectory behaviors are different than the ones of the non rotating black holes due to the cavity effect. Finally, we provide evidence for the existence of an universal ratio defined in terms of the photon sphere radius and the impact parameter. Concretely, we obtain a optical ratio \frac{b_{sp}}{r_{sp}} \sim \sqrt 3.