Effects of dark matter-baryon scattering on redshifted 21 cm signals
Effects of dark matter-baryon scattering on redshifted 21 cm signals
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暗物质-重子散射对红移 21 cm 信号的影响
DOI：
10.1103/physrevd.90.083522
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发表时间：
2014
影响因子：
5
通讯作者：
Joseph Silk
中科院分区：
文献类型：
--
作者：
Hiroyuki Tashiro;Kenji Kadota;Joseph Silk
我们证明了暗物质(DM)和重子之间的弹性散射可以影响早期星系间介质的热演化，并讨论了观测结果。结果表明，由于DM和重子之间的相互作用，重子温度在与CMB温度解耦后冷却。我们通过计算与速度相关的DM弹性散射截面共存的21厘米功率谱来说明我们的发现。例如，对于10GeV的DM质量，在CMB和大规模结构数据所限定的当前允许的DM-重子截面内，21G厘米的亮度温度角功率谱可以被抑制2倍。这种与尺度无关的角功率谱抑制对于具有共同截面的较小的Dm质量(例如，高达10倍的)甚至可以更大，鉴于即将到来的宇宙学调查，这种效应对于探索Dm的性质将非常有兴趣。
We demonstrate that elastic scattering between dark matter (DM) and baryons can affect the thermal evolution of the intergalactic medium at early epochs and discuss the observational consequences. We show that, due to the interaction between DM and baryons, the baryon temperature is cooled after decoupling from the CMB temperature. We illustrate our findings by calculating the 21 cm power spectrum in coexistence with a velocity-dependent DM elastic scattering cross section. For instance, for a DM mass of 10 GeV, the 21 cm brightness temperature angular power spectrum can be suppressed by a factor of 2 within the currently allowed DM-baryon cross section bounded by the CMB and large-scale structure data. This scale-independent suppression of the angular power spectrum can be even larger for a smaller DM mass with a common cross section (for instance, as large as a factor of 10 for), and such an effect would be of great interest for probing the nature of DM in view of forthcoming cosmological surveys.