In this work, we mainly focus on testing the spacetime properties around black holes surrounded by a dark fluid, which are potential candidates for dark energy described by the Chaplygin-like equation of state through its shadow. To do this, we first study the black hole’s horizon structure and shadow for the non-rotating case. Then, we obtain a rotating black hole solution in the presence of a dark fluid using the generalized Newman–Janis algorithm and study the effects of the black hole spin and the fluid parameters on the black hole horizons. Also, we obtained the shadow cast of the rotating black hole using celestial coordinates and showed that the presence of the dark fluid causes an increase in shadow size. Moreover, we use the shadow size of supermassive black holes Sagittarius A* and M87* from Event Horizon Telescope observations to obtain constraints on the spin, black hole charge, and dark fluid parameters. Lastly, we investigate the energy emission rate of a charged black hole surrounded by a Chaplygin-like dark fluid, comparing it to both rotating and non-rotating cases.

中文翻译：

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被暗流体包围的旋转黑洞的阴影，具有类 Chaplygin 状态方程和 EHT 结果的约束


在这项工作中，我们主要关注测试被暗流体包围的黑洞周围的时空特性，这些黑洞是类查普雷金状态方程通过其阴影描述的暗能量的潜在候选者。为此，我们首先研究非旋转情况下黑洞的视界结构和阴影。然后，我们使用广义Newman-Janis算法获得暗流体存在下的旋转黑洞解，并研究黑洞自旋和流体参数对黑洞视界的影响。此外，我们使用天体坐标获得了旋转黑洞的阴影投射，并表明暗流体的存在导致阴影尺寸的增加。此外，我们利用视界望远镜观测到的超大质量黑洞人马座 A* 和 M87* 的阴影大小来获得对自旋、黑洞电荷和暗流体参数的约束。最后，我们研究了被类查普雷金暗流体包围的带电黑洞的能量发射率，并将其与旋转和非旋转情况进行比较。