We construct a hybrid-inflation model where the inflaton potential is generated radiatively, as gauge symmetries guarantee it to be accidentally flat at tree level. The model can be regarded as a small-field version of natural inflation, with inflation ending when the mass of a second scalar, the waterfall field, turns tachyonic. This provides a minimal, robust realization of hybrid inflation, which predicts specific correlations among cosmic microwave background observables. Tachyonic preheating leads to the production of gravitational waves which, for a low inflationary scale, might be detected by upcoming experiments. Simple variations of the model can give rise to topological defects, such as unstable domain walls. Their dynamics produces a stochastic gravitational-wave background, which can be compatible with the recent detection by pulsar timing arrays.

中文翻译：

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来自意外光标量的混合膨胀波和引力波


我们构建了一个混合充气模型，其中膨胀电位是径向产生的，因为仪表对称性保证了它在树水平上意外平坦。该模型可以被视为自然膨胀的小场版本，当第二个标量（瀑布场）的质量变为超光速时，膨胀结束。这提供了混合膨胀的最小、稳健的实现，它预测了宇宙微波背景可观测对象之间的特定相关性。超速子预热导致引力波的产生，对于低膨胀尺度，引力波可能会被即将到来的实验检测到。模型的简单变化会导致拓扑缺陷，例如不稳定的域壁。它们的动力学产生了随机引力波背景，这与最近通过脉冲星计时阵列探测到的情况兼容。