We study the density profile of a dwarf halo in the decaying dark matter (DDM) cosmology, using a new algorithm that resolves halo density profiles down to the innermost $700$ pc robustly with high efficiency. Following Schwarzschild's orbit-based method, we have also developed a simplified model to calculate the DDM halo density profiles, which agree remarkably well with those from N-body simulations. Both zoom-in simulations and the simplified model reveal that dark matter decays lead to the flattening of central density and overall reduction of density in dwarf halos, and the underlying physics mechanisms are well illustrated by the simplified model. The slowly-rising scaled rotation curves of DDM dwarf halos agree with the observation of local dwarf galaxies. Our results suggest that the DDM holds great potential for resolving the small-scale problems faced by the cold dark matter (CDM) model.

中文翻译：

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暗物质衰变下矮光晕密度剖面的变形

我们研究了衰变暗物质 (DDM) 宇宙学中矮光晕的密度剖面，使用一种新算法，该算法可以高效稳定地解析最内部的 700 美元 pc 的晕密度剖面。遵循 Schwarzschild 的基于轨道的方法，我们还开发了一个简化模型来计算 DDM 晕密度剖面，该模型与 N 体模拟的结果非常吻合。放大模拟和简化模型都表明，暗物质衰变导致矮晕中心密度变平和密度整体降低，简化模型很好地说明了潜在的物理机制。DDM矮星晕的缓慢上升比例旋转曲线与当地矮星系的观测结果一致。