The Galactic Center (GC) of the Milky Way, thanks to its proximity, allows to perform astronomical observations that investigate physical phenomena at the edge of astrophysics and fundamental physics. As such, it offers a unique laboratory to probe gravity, where one can not only test the basic predictions of general relativity (GR), but is also able to falsify theories that, over time, have been proposed to modify or extend GR; to test different paradigms of dark matter; and to place constraints on putative models that have been formulated as alternatives to the standard black hole paradigm in GR. In this review we provide a general overview of the history of observations of the GC, emphasizing the importance, in particular on the smallest-observable scales, that they had in opening a new avenue to improve our understanding of the underlying theory of gravity in the surrounding of a supermassive compact object.

中文翻译：

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银河中心作为引力和暗物质理论的实验室


银河系的银河中心（GC）由于距离较近，可以进行天文观测，研究天体物理学和基础物理学边缘的物理现象。因此，它提供了一个独特的实验室来探测引力，在这里人们不仅可以测试广义相对论（GR）的基本预测，还可以证伪随着时间的推移而被提议修改或扩展广义相对论的理论；测试暗物质的不同范式；并对作为广义相对论中标准黑洞范式的替代方案而制定的假定模型施加限制。在这篇综述中，我们对 GC 的观测历史进行了总体概述，强调了其重要性，特别是在最小可观测尺度上，它们为提高我们对引力理论的理解开辟了一条新途径。超大质量致密天体的周围。