标题： 近轴引力透镜事件的统计学 显示英文标题

标题： The Statistics of Nearly On-Axis Gravitational Lensing Events

摘要： 一个很小的空间体积，相对于给定的光源来说几乎在引力透镜的轴后方，将接收到显著增加的辐射通量。 在点质量透镜对完全孤立的点光源起作用的理想化情况下，只有当通量趋于无穷大时，体积才会趋近于零；事实上，体积加权的均方根通量是发散的。 在现实情况下，有限的源尺寸和其他引力偏折效应（即非零剪切）会限制最大通量，并大大复杂化物理过程，但仍然会在小体积内产生非常大的通量。 我们考虑这些极端引力透镜事件（EGLE）的物理和统计特性，并对各种已知和假定的透镜物体和源群体的可能天体物理效应进行了初步考察，特别关注源尺寸有限但剪切不重要的情况。 显示英文摘要

摘要： A small volume of space, nearly on-axis behind a gravitational lens with respect to a given source, will receive a greatly increased radiation flux. In the idealized case of a point mass lens acting on a point source in complete isolation, the volume will approach zero only as the flux tends to infinity; in fact, the volume weighted rms flux is divergent. In realistic cases, finite source size and the effects of other gravitational deflections (i.e., non-zero shear) limit the maximum flux and considerably complicate the physics, but very large fluxes are still produced in small volumes. We consider the physics and statistics of these Extreme Gravitational Lensing Events (EGLE) and present an initial examination of their possible astrophysical effects for various known and putative populations of lensing objects and sources, with particular attention to the case in which finite source size is important but shear is not.