论文标题
观察中的光挠度：在Sitter时空上的两个无效的大地测量学之间的角度差异，具有多镜头对象
Light deflection in Observation: Angle differences between two null geodesics on the de Sitter spacetime with multi-lensing objects
论文作者
论文摘要
我们在带有多镜头对象的DE Sitter时空上得出了两个无效的测量学之间的角度差，从光源传播到观察者。假设镜头对象是De Sitter背景上的质量单孔，我们通过扰动地求解爱因斯坦方程来得出度量张量。在该时空上，我们求解了通过坐标时间参数的无效参数。使用无效的测量学，我们以坐标不变的方式定义角度差。我们将相对论效应持续到扰动的一阶，并阐明近似误差的幅度。我们发现看到各向同性宇宙空间的其余观察者隐含地观察了宇宙常数对通过光源位置的角度差异的影响。作为一种实际应用，我们将银河中心（SGR A*）的巨大黑洞和太阳系作为镜头对象，进一步是恒星和围绕Sgr a*的耀斑，作为光源。我们使用它们的空间坐标来编写这些光源之间的角度差异。我们发现，SGR A*的偏转保持在角度差异，而太阳系的挠度则取消到扰动的第一阶。 SGR a*的偏转量约为10个微弧秒，这在不久的将来的观察结果中可检测到。
We derive angle differences between two null geodesics, propagating from light sources to an observer, on the de Sitter spacetime with multi-lensing objects. Assuming the lensing objects are mass monopoles on the de Sitter background, we derive the metric tensor by solving the Einstein equation perturbatively. On that spacetime, we solve a null geodesic parametrized by the coordinate time. Using the null geodesics, we define the angle differences in a coordinate invariant way. We take in the relativistic effects up to the first order of perturbation and clarify the magnitude of approximation errors. We find that the rest observer, who sees the isotropic cosmic space, implicitly observes the effect of the cosmological constant on the angle differences through the positions of the light sources. As a practical application, we regard the massive black hole at our galactic center (Sgr A*) and the solar system as the lensing objects, further a star and a flare around Sgr A* as the light sources. We write the angle differences between these light sources using their spatial coordinates. We find that deflections by Sgr A* remain in the angle differences while deflections by the solar system cancel out up to the first order of perturbation. The deflections by Sgr A* amounts around 10 microarcseconds, which is detectable in the near future observations.
