We consider a class of helical phase inflation models from the ${\mathcal N}=1$ supergravity where the phase component of a complex field acts as an inflaton. This class of models avoids the eta problem in supergravity inflation due to the phase monodromy of the superpotential. We study the inflationary predictions of this class of models in the context of both standard and large extra dimensional brane cosmology, and find that they can easily accommodate the Planck 2018 and BICEP2 constraints. We find that the helical phase inflation has $\alpha$-attractors and the attractors depend on one model parameter only.

中文翻译：

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螺旋相膨胀及其观测约束

我们考虑了一类来自 ${\mathcal N}=1$ 超重力的螺旋相位膨胀模型，其中复杂场的相位分量充当膨胀子。这类模型避免了由于超势的相位单一性导致的超重力膨胀中的eta问题。我们在标准和大型超维膜宇宙学的背景下研究了这类模型的暴胀预测，发现它们可以轻松适应普朗克 2018 和 BICEP2 的约束。我们发现螺旋相膨胀具有 $\alpha$-吸引子，并且这些吸引子仅取决于一个模型参数。