论文标题
机器学习宇宙通货膨胀
Machine learning cosmic inflation
论文作者
论文摘要
我们根据遗传算法(GA)提出了一种机器学习方法,该方法可用于直接从宇宙学数据中重建通货膨胀电位。我们创建了一个由GA,原始代码和用于计算理论预测的Boltzmann代码组成的管道,以及宇宙微波背景(CMB)数据。作为概念证明,我们将方法应用于普朗克CMB数据,并以非参数但分析的方式探索单场通货膨胀潜力的功能空间。我们表明,算法很容易改善二次通胀的香草模型,并提出了更适合数据的缓慢滚动电势,而我们确认了Starobinsky通货膨胀模型(和其他小型模型)的鲁棒性。此外,使用未扣除的CMB数据,我们通过以不可知论的方式搜索潜力中的振荡特征,对GA进行了第一个具体应用,并在最佳的无功能潜力上找到了非常重大的改进,$Δχ^2 <-20 $。这些令人鼓舞的初步结果激发了在原始功率谱中搜索具有频率多模式分布的共振特征。我们强调的是,我们的管道是模块化的,可以很容易地扩展到其他CMB数据集和通货膨胀方案,例如多场通货膨胀或具有高阶导数的理论。
We present a machine-learning approach, based on the genetic algorithms (GA), that can be used to reconstruct the inflationary potential directly from cosmological data. We create a pipeline consisting of the GA, a primordial code and a Boltzmann code used to calculate the theoretical predictions, and Cosmic Microwave Background (CMB) data. As a proof of concept, we apply our methodology to the Planck CMB data and explore the functional space of single-field inflationary potentials in a non-parametric, yet analytical way. We show that the algorithm easily improves upon the vanilla model of quadratic inflation and proposes slow-roll potentials better suited to the data, while we confirm the robustness of the Starobinsky inflation model (and other small-field models). Moreover, using unbinned CMB data, we perform a first concrete application of the GA by searching for oscillatory features in the potential in an agnostic way, and find very significant improvements upon the best featureless potentials, $Δχ^2 < -20$. These encouraging preliminary results motivate the search for resonant features in the primordial power spectrum with a multimodal distribution of frequencies. We stress that our pipeline is modular and can easily be extended to other CMB data sets and inflationary scenarios, like multifield inflation or theories with higher-order derivatives.