Intensity maps of the 21cm emission line of neutral hydrogen are lensed by intervening large-scale structure, similar to the lensing of the cosmic microwave background temperature map. We extend previous work by calculating the lensing contribution to the full-sky 21cm bispectrum in redshift space. The lensing contribution tends to peak when equal-redshift fluctuations are lensed by a lower redshift fluctuation. At high redshift, lensing effects can become comparable to the contributions from density and redshift-space distortions.

中文翻译：

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透镜对 21cm 强度双谱的贡献

中性氢 21cm 发射线的强度图是通过介入大尺度结构透镜化的，类似于宇宙微波背景温度图的透镜化。我们通过计算红移空间中全天空 21 厘米双谱的透镜贡献来扩展先前的工作。当等红移波动被较低的红移波动透镜化时，透镜效应趋于达到峰值。在高红移时，透镜效应可以与密度和红移空间畸变的贡献相媲美。