标题： f(R)模型中引力波的频谱 显示英文标题

标题： The spectrum of gravitational waves in an f(R) model with a bounce

摘要： 我们提出一个在度规$f(R)$理论中由反弹前导的膨胀模型。 在这个模型中，修改的引力仅影响宇宙的早期阶段。 我们使用 Bogoliubov 系数的方法分析此情景中引力波的预测谱。 我们表明，在非常低的频率下，谱上有明显的（振荡）信号；即，对应于目前进入视界的模式。 显示英文摘要

摘要： We present an inflationary model preceded by a bounce in a metric $f(R)$ theory. In this model, modified gravity affects only the early stages of the universe. We analyse the predicted spectrum of the gravitational waves in this scenario using the method of the Bogoliubov coefficients. We show that there are distinctive (oscillatory) signals on the spectrum for very low frequencies; i.e., corresponding to modes that are currently entering the horizon.