Probing oscillons of ultra-light axion-like particle by 21 cm forest
Probing oscillons of ultra-light axion-like particle by 21 cm forest
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DOI：
10.1088/1475-7516/2021/04/019
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发表时间：
2020-10
影响因子：
6.4
通讯作者：
M. Kawasaki;Wakutaka Nakano;Hiromasa Nakatsuka;Eisuke Sonomoto
中科院分区：
文献类型：
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作者：
M. Kawasaki;Wakutaka Nakano;Hiromasa Nakatsuka;Eisuke Sonomoto
超轻类轴子粒子（Ultra-Light Axion-like Particle，简称UNOPS）是解决天体物理中小尺度问题的一种方法。当这样一个标量粒子在一个比二次方势更浅的势场中以1/2的振幅振荡时，它可以形成一个局域的致密物体，即量子。𝒪由于绝热不变量的近似守恒，它的寿命很长，因此它可以以红移z（10）的形式存在到最近的宇宙中。𝒪受这些中微子影响的尺度由中微子质量m决定，并可通过21 cm线的观测来检测。本文研究了用21 cm谱线探测中微子的可能性，发现当m = 10-19 eV时，中微子能增强21 cm谱线的观测信号，并且中微子与暗物质的比值远大于10-2，这取决于势的形式。
Ultra-Light Axion-like Particle (ULAP) is motivated as one of the solutions to the small scale problems in astrophysics. When such a scalar particle oscillates with an 𝒪(1) amplitude in a potential shallower than quadratic, it can form a localized dense object, oscillon. Because of its longevity due to the approximate conservation of the adiabatic invariant, it can survive up to the recent universe as redshift z ∼𝒪(10). The scale affected by these oscillons is determined by the ULAP mass m and detectable by observations of 21 cm line. In this paper, we examine the possibility to detect ULAP by 21 cm line and find that the oscillon can enhance the signals of 21 cm line observations when m ≲ 10-19 eV and the fraction of ULAP to dark matter is much larger than 10-2 depending on the form of the potential.