Explicit form of the Scalar-Tensor metric to be used for propagation of light in the Solar system in continuity of the GR IAU2000 metric

The Second Post-Newtonian Light Propagation and Its Astrometric Measurement in the Solar System

The relativistic theories of light propagation are generalized by introducing two new parameters $ς$ and $η$ in the second post-Newtonian (2PN) order, in addition to the parameterized post-Newtonian parameters $γ$ and $β$. This new 2PN parameterized (2PPN) formalism includes the non-stationary gravitational fields and the influences of all kinds of relativistic effects. The multipolar components of gravitating bodies are taken into account as well at the first post-Newtonian order. The equations of motion and their solutions of this 2PPN light propagation problem are obtained. Started from the…

Scalar-tensor propagation of light in the inner solar system at the millimetric level

In a recent paper [1], motivated by forthcoming space experiments involving propagation of light in the Solar System, we have proposed an extention of the IAU metric equations at the c-4 level in General Relativity. However, scalar-tensor theories may induce corrections numerically comparable to the c-4 general relativistic terms. Accordingly, one first proposes in this paper an extension of [1] to the scalar-tensor case. The case of a hierarchized system (such as the Solar system) is emphasized. In this case, the relevant metric solution is proposed. Then, the geodesic solution relevant for p…

TianQin激光传播中的太阳等离子体噪声：极端案例与统计分析

Solar Plasma Noise in TianQin Laser Propagation: An Extreme Case and Statistical Analysis

本研究基于MHD模拟极强太阳爆发，发现激光传播噪声在Michelson组合下接近TianQin位移噪声要求的100%，并揭示其与太阳风动压等参数线性相关，证实时延干涉测量可显著抑制该噪声发生率。

Light propagation in the gravitational field of N arbitrarily moving bodies in the 1.5PN approximation for high-precision astrometry

High-precision astrometry on sub-micro-arcsecond level in angular resolution requires accurate determination of the trajectory of a light-signal from the celestial light source through the gravitational field of the Solar system toward the observer. In this investigation the light trajectory in the gravitational field of N moving bodies is determined in the 1.5 post-Newtonian approximation. In the approach presented two specific issues of particular importance are accounted for: (1) According to the recommendations of International Astronomical Union, the metric of the Solar system is expresse…

静止物体单极和四极场中2PN近似的光传播：边值问题

Light propagation in the 2PN approximation in the monopole and quadrupole field of a body at rest: Boundary value problem

本研究从2PN近似下光传播的初值问题推导出边值问题的解，为太阳系超高精度光偏转和时间延迟测试奠定基础。

Influence of Dark Matter on Light Propagation in Solar System

We investigated the influence of dark matter on light propagation in the solar system. We assumed the spherical symmetry of spacetime and derived the approximate solution of the Einstein equation, which consists of the gravitational attractions caused by the central celestial body, i.e. the Sun, and the dark matter surrounding it. We expressed the dark matter density in the solar system in the following simple power-law form, $\varrho(t, r) = ρ(t)(\ell/r)^k$, where $t$ is the coordinate time; $r$, the radius from the central body; $\ell$, the normalizing factor; $k$, the exponent characterizin…