The thermal freeze-out mechanism for relic dark matter heavier than $O(10-100 $ TeV$)$ requires cross-sections that violate perturbative unitarity. Yet the existence of dark matter heavier than these scales is certainly plausible from a particle physics perspective, pointing to the need for a non-thermal cosmological history for such theories. Topological dark matter is a well-motivated scenario of this kind. Here the hidden-sector dark matter can be produced in abundance through the Kibble-Zurek mechanism describing the non-equilibrium dynamics of defects produced in a second order phase transition. We revisit the original topological dark matter scenario, focusing on hidden-sector magnetic monopoles, and consider more general cosmological histories. We find that a monopole mass of order ($1-10^5$) PeV is generic for the thermal histories considered here, if monopoles are to entirely reproduce the current abundance of dark matter. In particular, in a scenario involving an early era of matter domination, the monopole number density is always less than or equal to that in a pure radiation dominated equivalent provided a certain condition on critical exponents is satisfied. This results in a larger monopole mass needed to account for a fixed relic abundance in such cosmologies.

中文翻译：

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物质支配的隐藏扇区单极子暗物质

重于 $O(10-100 $TeV$)$ 的残余暗物质的热冻结机制需要违反微扰幺正性的横截面。然而，从粒子物理学的角度来看，比这些尺度更重的暗物质的存在肯定是合理的，这表明这些理论需要非热宇宙学历史。拓扑暗物质就是这种动机良好的场景。在这里，可以通过描述二阶相变中产生的缺陷的非平衡动力学的 Kibble-Zurek 机制大量产生隐藏扇区暗物质。我们重新审视最初的拓扑暗物质场景，重点关注隐藏扇区磁单极子，并考虑更一般的宇宙学历史。我们发现，如果单极子要完全重现当前的暗物质丰度，那么单极子质量（$1-10^5$）PeV 对于这里考虑的热历史是通用的。特别是，在涉及早期物质支配时代的场景中，只要满足临界指数的特定条件，单极子数密度总是小于或等于纯辐射支配等价物。这导致需要更大的单极子质量来解释此类宇宙学中固定的遗迹丰度。只要满足临界指数的特定条件，单极子数密度总是小于或等于纯辐射主导等效中的单极子数密度。这导致需要更大的单极子质量来解释此类宇宙学中固定的遗迹丰度。只要满足临界指数的特定条件，单极子数密度总是小于或等于纯辐射主导等效中的单极子数密度。这导致需要更大的单极子质量来解释此类宇宙学中固定的遗迹丰度。