标题： 衍射微透镜 III：天体测量特征 显示英文标题

标题： Diffractive Microlensing III: Astrometric Signatures

摘要： 引力透镜通常是在几何光学极限下处理的；然而，当辐射的波长接近或超过透镜的史瓦西半径时，衍射变得重要。尽管由衍射引力透镜产生的增益已经被很好地理解，但本文首次推导了衍射微透镜的天文学标志，同时还给出了天文学位移的一个简单的封闭形式界限。这个简单的界限给出了太阳邻域中亚恒星透镜在20 GHz处观测到的最大位移，这些观测可以通过高灵敏度、高角分辨率的射电望远镜（如提议中的平方公里阵列SKA）实现。 显示英文摘要

摘要： Gravitational lensing is generally treated in the geometric optics limit; however, when the wavelength of the radiation approaches or exceeds the Schwarzschild radius of the lens, diffraction becomes important. Although the magnification generated by diffractive gravitational lensing is well understood, the astrometric signatures of diffractive microlensing are first derived in this paper along with a simple closed-form bound for the astrometric shift. This simple bound yields the maximal shifts for substellar lenses in solar neighbourhood observed at 20~GHz, accessible to high sensitivity, high angular resolution radio telescopes such as the proposed Square Kilometre Array (SKA).