标题： 大尺度结构对引力透镜像位置和时间延迟的影响 显示英文标题

标题： Large Scale Structure Effects on the Gravitational Lens Image Positions and Time Delay

摘要： 我们计算由大尺度结构相关性引起的引力透镜图像位置和时间延迟的涨落。 我们表明这些涨落可以表示为密度功率谱上的简单积分。 使用{\sl COBE}归一化，我们发现宇宙距离处的物体位置预计会偏离其真实位置几角分。 这些偏移无法直接观测。 图像之间的相对位置涨落约为相对分离的百分之几，这意味着不期望由大尺度结构产生多个图像。 然而，这些涨落大于位置的观测误差，并影响透镜势的重建。 时间延迟涨落具有几何贡献和引力贡献。 两者都远大于主透镜的预期时间延迟，但部分相互抵消。 我们发现大尺度结构对时间延迟的影响较弱，时间延迟测量可以作为探测宇宙距离尺度的工具。 显示英文摘要

摘要： We compute the fluctuations in gravitational lens image positions and time delay caused by large scale structure correlations. We show that these fluctuations can be expressed as a simple integral over the density power spectrum. Using the {\sl COBE} normalization we find that positions of objects at cosmological distances are expected to deviate from their true positions by a few arcminutes. These deflections are not directly observable. The positions of the images relative to one another fluctuate by a few percent of the relative separation, implying that one does not expect multiple images to be produced by large scale structures. Nevertheless, the fluctuations are larger than the observational errors on the positions and affect reconstructions of the lens potential. The time delay fluctuations have a geometrical and a gravitational contribution. Both are much larger than the expected time delay from the primary lens, but partially cancel each other. We find that large scale structure weakly affects the time delay and time delay measurements can be used as a probe of the distance scale in the universe.