标题： 惰性中微子暗物质的共振产生与改进的数值方案 显示英文标题

标题： Resonant production of sterile neutrino dark matter with a refined numerical scheme

摘要： 大原始中微子不对称性的存在是一个引人入胜的可能性，无论在观测上还是理论上都是如此。 这种不对称性可能导致$\mathrm{keV}$规模的惰性中微子共振产生，这是一类引人注目的暗物质候选者。 在本文中，我们通过一种改进的数值分析全面重新审视了共振产生过程，采用动量模式的动力学离散化方法来处理共振的尖锐性。 我们找到了与X射线和 Lyman-$\alpha$约束一致的参数区域，对于轻子-熵比$\gtrsim \mathcal{O}(10^{-3})$和$m_{\nu_s}\gtrsim 20$keV。 我们还探讨了 Affleck-Dine 机制作为这种不对称性的可能起源。 虽然之前的研究考虑了轻子数生成之后的共振产生，但我们数值研究了在轻子数注入期间部分惰性中微子被产生的案例。 在这个区域内，某些参数集可以缩短自由流长度并减少所需的混合角以匹配观测到的暗物质丰度，从而缓解观测约束。 显示英文摘要

摘要： The existence of a large primordial neutrino asymmetry is an intriguing possibility, both observationally and theoretically. Such an asymmetry can lead to the resonant production of $\mathrm{keV}$-scale sterile neutrinos, which are a fascinating candidate for dark matter. In this paper, we comprehensively revisit the resonant production processes with a refined numerical analysis, adopting a dynamical discretization of momentum modes to take care of the sharpness of the resonance. We find parameter regions consistent with X-ray and Lyman-$\alpha$ constraints for lepton-to-entropy ratio $\gtrsim \mathcal{O}(10^{-3})$ and $m_{\nu_s}\gtrsim 20$\,keV. We also explore the Affleck-Dine mechanism as a possible origin for such asymmetries. While previous studies considered resonant production after lepton number generation, we numerically investigate cases where a fraction of sterile neutrinos is produced during lepton number injection. In this regime, some parameter sets can shorten the free-streaming length and reduce the required mixing angle to match the observed dark matter abundance, thereby mitigating the observational constraints.