具有均匀等离子体的一般静态和球对称时空中的光线偏折
Light deflection in general static and spherically symmetric spacetime with a homogeneous plasma
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中文总结 AI 辅助
研究一般静态和球对称时空中光线偏折角，开发微扰技术计算，结果表明等离子体增大偏折角，与数值积分吻合，公式应用于多种时空并讨论影响；附录重新计算并比较偏折角。
中文摘要 AI 辅助
我们在这项工作中开发了一种微扰技术，用于计算具有均匀非磁性等离子体的一般静态和球对称时空中光线的偏折角。偏折角表示为$M/b$的幂级数，其中$M$和$b$分别是时空质量和光线的碰撞参数。级数系数是度规函数渐近展开系数和渐近折射率倒数的多项式。当等离子体稀薄时，偏折角也可表示为$M/b$与电子等离子体频率和渐近光子频率之比的对偶级数。级数结果表明，对于一般的SSS时空，等离子体在主导阶总是增大偏折角，从而增加引力透镜图像的视角度。然后表明偏折角的这些级数结果与数值积分得到的结果非常吻合。偏折角的一般公式随后应用于雷斯纳 - 诺德斯特龙、带电霍恩德斯基和带电伽利略时空。简要讨论了等离子体和时空特征参数对这些时空中偏折角的影响。在附录中，重新计算了先前尝试的时空中的偏折角并与文献进行了比较。
英文摘要
We developed in this work a perturbative technique to compute the deflection angle of light rays in general static and spherically symmetric spacetimes with a homogeneous non-magnetic plasma. The deflection angle is expressed as a power series of $M/b$ with $M$ and $b$ being the spacetime mass and the impact parameter of the ray. The series coefficients are polynomials of the asymptotic expansion coefficients of the metric functions and the reciprocal of the asymptotic refractive index. When the plasma is dilute, the deflection angle can also be expressed as a dual series of $M/b$ and the frequency ratio between the electron plasma frequency and the asymptotic photon frequency. The series result reveals that for general SSS spacetime, the plasma at the leading order always enhances the deflection angle and therefore increases the apparent angles of the gravitational lensing images. These series results of the deflection angle are then shown to have excellent agreement with those obtained using numerical integration. The general formula of the deflection angle is then applied to the Reissner-Nordström, charged Horndeski and charged Galileon spacetimes. The effect of the plasma and characteristic parameter of the spacetimes on the deflection angles in these spacetimes was briefly discussed. In the appendix, the deflection angles in previously attempted spacetimes are re-computed and compared with the literature.
