Screening mechanisms allow light scalar fields to dynamically avoid the constraints that come from our lack of observation of a long-range fifth force. Galactic scale tests are of particular interest when the light scalar is introduced to explain the dark matter or dark energy that dominates our cosmology. To date, much of the literature that has studied screening in galaxies has described screening using simplifying approximations. In this work, we calculate numerical solutions for scalar fields with screening mechanisms in galactic contexts, and use these to derive new, precise conditions governing where fifth forces are screened. We show that the commonly used binary screened/unscreened threshold can predict a fifth force signal in situations where a fuller treatment does not, leading us to conclude that existing constraints might be overestimated. We show that various other approximations of the screening radius provide a more accurate proxy to screening, although they fail to exactly reproduce the true screening surface in certain regions of parameter space. As a demonstration of our scheme, we apply it to an idealised Milky Way and thus identify the region of parameter space in which the solar system is screened.

中文翻译：

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星系中标量第五力筛选的精确计算

筛选机制允许光标量场动态地避免由于我们缺乏对远程第五力的观察而产生的限制。当引入光标量来解释主导我们宇宙学的暗物质或暗能量时，银河尺度测试特别令人感兴趣。迄今为止，许多研究星系筛选的文献都描述了使用简化近似的筛选。在这项工作中，我们在银河背景下计算具有筛选机制的标量场的数值解，并使用这些来导出新的、精确的条件来控制第五力的筛选位置。我们表明，常用的二元筛选/未筛选阈值可以在更全面的治疗无法预测的情况下预测第五种力信号，这使我们得出结论，现有的约束可能被高估了。我们表明，各种其他的筛选半径近似值提供了更准确的筛选代理，尽管它们无法在参数空间的某些区域准确地再现真实的筛选表面。作为我们方案的演示，我们将其应用于理想化的银河系，从而确定了太阳系被屏蔽的参数空间区域。