Gravitational lensing in a cold dark matter universe
Gravitational lensing in a cold dark matter universe
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冷暗物质宇宙中的引力透镜
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
S. White
中科院分区：
文献类型：
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作者：
R. Narayan;S. White
利用Press-Schechter（1974）理论研究了有偏冷暗物质（CDM）宇宙中由于质量凝聚引起的引力透镜效应。在CDM晕的核心半径很小的关键假设下，高Z透镜类星体的像角间距分布的峰值约为1角秒，半宽约为10倍。考虑到小角度分离时的选择效应，这与观察到的分离很好地吻合。透镜效应的频率估计是略低于所观察到的，但可以通过调用放大偏置和通过在CDM模型中假设的密度波动幅度的一个小的向上调整来消除这种差异。
Gravitational lensing due to mass condensations in a biased cold dark matter (CDM) universe is investigated using the Press-Schechter (1974) theory with density fluctuation amplitudes taken from previous N-body work. Under the critical assumption that CDM haloes have small core radii, a distribution of image angular separations for high-z lensed quasars with a peak at about 1 arcsec and a half-width of a factor of about 10. Allowing for selection effects at small angular separations, this is in good agreement with the observed separations. The estimated frequency of lensing is somewhat lower than that observed, but the discrepancy can be removed by invoking amplification bias and by making a small upward adjustment to the density fluctuation amplitudes assumed in the CDM model.