Evolution and thermalization of dark matter axions in the condensed regime
Evolution and thermalization of dark matter axions in the condensed regime
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DOI：
10.1103/physrevd.87.085010
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发表时间：
2012-10
影响因子：
5
通讯作者：
K. Saikawa;Masahide Yamaguchi
中科院分区：
文献类型：
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作者：
K. Saikawa;Masahide Yamaguchi
我们讨论了暗物质轴子由于引力自相互作用而形成玻色-爱因斯坦凝聚（BEC）的可能性。BEC的形成发生在凝聚态，其中不同动量状态之间的跃迁速率与跃迁中交换的能量相比是大的。基于内-内形式，导出了凝聚态下轴子量子态占据数随时间的演化。我们恢复了在其他文献中得到的轴子场自相互作用热化率的表达式。研究还发现，轴子与其他粒子相互作用的首阶贡献消失，这意味着轴子BEC对标准宇宙学参数没有任何显著的修正.
We discuss the possibility that dark matter axions form a Bose-Einstein condensate (BEC) due to the gravitational self-interactions. The formation of BEC occurs in the condensed regime, where the transition rate between different momentum states is large compared to the energy exchanged in the transition. The time evolution of the quantum state occupation number of axions in the condensed regime is derived based on the in-in formalism. We recover the expression for the thermalization rate due to self interaction of the axion field, which was obtained in the other literature. It is also found that the leading order contributions for interactions between axions and other species vanish, which implies that the axion BEC does not give any significant modifications on standard cosmological parameters.