A large class of scalar-tensor theories of gravity exhibit a screening mechanism that dynamically suppresses fifth forces in the Solar system and local laboratory experiments. Technically, at the scalar field equation level, this usually translates into nonlinearities which strongly limit the scope of analytical approaches. This article presents $femtoscope$ $-$ a Python numerical tool based on the Finite Element Method (FEM) and Newton method for solving Klein-Gordon-like equations that arise in particular in the symmetron or chameleon models. Regarding the latter, the scalar field behavior is generally only known infinitely far away from the its sources. We thus investigate existing and new FEM-based techniques for dealing with asymptotic boundary conditions on finite-memory computers, whose convergence are assessed. Finally, $femtoscope$ is showcased with a study of the chameleon fifth force in Earth orbit.

翻译：大量的星际- 狭重重理论展示了一种能动态抑制太阳系和地方实验室实验第五股力的筛选机制。 从技术上讲,在星际场方程式一级,这通常会转化为非线性,严重限制了分析方法的范围。本文章介绍了一种基于“精度元素法”和“牛顿方法”的“金色镜”数字工具,用以解决特别在交响器或色米伦模型中产生的克莱因- 哥顿式方程式。关于后者,星际场行为一般只在远离其源头的地方广为人知。因此,我们调查了现有和新的“FEM”基技术,用以处理有限模量计算机上的无线边界条件,这些计算机的趋同性得到了评估。最后,用对地球轨道上的色粒子第五股力的研究展示了美元。