The dark matter annihilation channels sometimes involve sharp resonances. In such cases the usual momentum averaged approximations for computing the DM abundance may not be accurate. We develop an easily accessible momentum dependent framework for computing the DM abundance accurately and efficiently near such features. We apply the method to the case of a singlet scalar dark matter $s$ interacting with SM through higgs portal $\lambda_{\rm hs}s^2 h^2$ and compare the results with different momentum averaged methods. The accuracy of the latter depend strongly on the strength of the elastic interactions and corrections are large if WIMP has negligible interactions beyond the main annihilation channel. In the singlet scalar model however, the standard model scatterings induce an efficient kinetic equilibrium that validates the momentum averaged computation to 20 per cent accuracy. We update the current extent of the allowed region in the light singlet scalar dark matter to $m_{\rm S} \in [56,62.5]$ GeV.

中文翻译：

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暗物质遗迹丰度的精确计算

暗物质湮灭通道有时涉及尖锐的共振。在这种情况下，通常用于计算 DM 丰度的动量平均近似值可能不准确。我们开发了一个易于访问的动量依赖框架，用于在这些特征附近准确有效地计算 DM 丰度。我们将该方法应用于单线态标量暗物质 $s$ 通过 higgs 门户 $\lambda_{\rm hs}s^2 h^2$ 与 SM 相互作用的情况，并将结果与​​不同的动量平均方法进行比较。后者的准确性在很大程度上取决于弹性相互作用的强度，如果 WIMP 在主湮灭通道之外的相互作用可以忽略不计，则修正量很大。然而，在单线态标量模型中，标准模型散射诱导了有效的动力学平衡，可验证动量平均计算的准确度为 20%。我们将轻单线态标量暗物质中允许区域的当前范围更新为 $m_{\rm S} \in [56,62.5]$ GeV。