We investigate the generation of features at large scales in the primordial power spectrum (PPS) when inflation is driven by two scalar fields. In canonical single field models of inflation, these features are often generated due to deviations from the slow-roll regime. While deviations from slow-roll can be naturally achieved in two field models due to a sharp turn in the trajectory in the field space, features at the largest scales of the types suggested by CMB temperature anisotropies are more difficult to achieve in models involving two canonical scalar fields due to the presence of isocurvature fluctuations. We show instead that a coupling between the kinetic terms of the scalar fields can easily produce such features. We discuss models whose theoretical predictions are consistent with current observations and highlight the implications of our results.

中文翻译：

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在两个场膨胀模型中大规模生成原始特征

我们研究了当膨胀由两个标量场驱动时，原始功率谱 (PPS) 中大规模特征的生成。在典型的单场暴胀模型中，这些特征通常是由于与慢滚机制的偏差而产生的。虽然由于场空间中轨迹的急转弯，可以在两个场模型中自然地实现慢滚的偏差，但在涉及两个规范的模型中，CMB 温度各向异性建议的类型的最大尺度的特征更难实现。由于存在等曲率波动而产生的标量场。相反，我们展示了标量场的动力学项之间的耦合可以很容易地产生这样的特征。