We study the evolution of various measures of quantumness of the curvature perturbation by integrating out the inaccessible entropic fluctuations in the multi-field models of inflation. In particular, we discuss the following measures of quantumness, namely purity, entanglement entropy and quantum discord. The models being considered in this work are ones that produce large scale curvature power spectra similar to those produced by single-field models of inflation. More specifically, we consider different multi-field models which generate nearly scale invariant and oscillatory curvature power spectrum and compare their quantum signatures in the perturbations with the corresponding single-field models. We find that, even though different models of inflation may produce the same observable power spectrum on large scales, they have distinct quantum signatures arising from the perturbation modes. This may allow for a way to distinguish between different models of inflation based on their quantum signatures. Intriguingly, this result generalizes to bouncing scenarios as well.

我们通过整合暴涨多场模型中难以达到的熵涨落来研究曲率扰动量子性的各种度量的演化。我们特别讨论了以下量子性度量，即纯度、纠缠熵和量子不和谐。这项工作中考虑的模型是产生大尺度曲率功率谱的模型，类似于单场暴胀模型产生的模型。更具体地说，我们考虑不同的多场模型，这些模型产生近尺度不变和振荡曲率功率谱，并将其扰动中的量子特征与相应的单场模型进行比较。我们发现，尽管不同的暴胀模型可能在大尺度上产生相同的可观测功率谱，但它们具有由扰动模式产生的不同的量子特征。这可能允许一种根据量子特征区分不同膨胀模型的方法。有趣的是，这个结果也适用于弹跳场景。