标题： 扰动f(R)引力的实用解决方案 显示英文标题

标题： Practical solutions for perturbed f(R) gravity

摘要： 我们检查准静态近似和在f(R)引力理论中用于演化线性扰动的常见参数形式的准确性，并放置宇宙学约束。 特别是，我们分析了通常被忽略的近视界效应的性质和重要性。 我们发现，对于可行模型，当标量场的当前值较小时，这些修正完全可以忽略不计，对观测结果没有影响。 我们还发现，常用于表示f(R)中线性扰动修改方程的一参数形式会导致相对较小的理论系统误差，因此对于放置f(R)模型的约束是足够的。 显示英文摘要

摘要： We examine the accuracy of the quasi-static approximation and a parametric form commonly employed for evolving linear perturbations in f(R) gravity theories and placing cosmological constraints. In particular, we analyze the nature and the importance of the near horizon effects that are often neglected. We find that for viable models, with a small present value of the scalaron field, such corrections are entirely negligible with no impact on observables. We also find that the one-parameter form, commonly used to represent the modified equations for linear perturbations in f(R), leads to theoretical systematic errors that are relatively small and, therefore, is adequate for placing constraint on f(R) models.