轴子景观中的灾难性暴胀
Catastrophic Inflation in the Axiverse
中文总结 AI 辅助
该研究在IIB型弦理论紧化景观中，通过算法识别出轴子势的灾难性合并灾变，实现无需大场范围的小场慢滚暴胀，部分结果符合观测的谱倾斜或标量扰动振幅。
中文摘要 AI 辅助
在IIB型弦理论在卡拉比-丘三维流形的O3/O7定向平凡化的紧化景观中，我们假设卡拉比-丘总体积可稳定在某些调谐值上，从而在特定几何结构的轴子势中识别出支持小场暴胀的区域。在调谐体积处，轴子势的多个临界点在一次“灾变”中合并，形成具有小梯度和小海森行列式的区域——这是慢滚暴胀的必要条件。我们描述了一种算法，可识别出多个此类灾变的明确示例，这些示例具有小场范围$f / M_{\rm Pl} \ll 1$，却能暴胀数千个e折叠。部分示例正确重现了观测到的谱倾斜，但未重现标量扰动的振幅；另一些示例则重现了观测到的振幅，但倾斜略偏红。我们所有示例均具有可忽略的张量扰动，且慢滚阶段未产生显著的非高斯性。我们的结果表明，只要凯勒模可稳定在体积的特殊值上，弦理论轴子无需对齐或大场范围即可成为宇宙暴胀的源。
英文摘要
In the landscape of compactifications of type IIB string theory on O3/O7 orientifolds of Calabi--Yau threefolds, we identify regions of the axion potential in specific geometries that support small-field inflation, under the assumption that the overall Calabi--Yau volume can be stabilized at certain tuned values. At the tuned volume multiple critical points of the axion potential merge in a ``catastrophe'', creating a region with small gradient and small Hessian determinant --- necessary conditions for slow-roll inflation. We describe an algorithm that identifies several explicit examples of these catastrophes that have small field range $f / M_{\rm Pl} \ll 1 $ yet inflate for thousands of efolds. Some examples correctly reproduce the observed spectral tilt but not the amplitude of scalar perturbations, while others reproduce the observed amplitude but with a tilt that is slightly too red. All our examples have negligible tensor perturbations and no significant non-Gaussianity generated during the slow-roll phase. Our results demonstrate that string theory axions can be the source of cosmic inflation without alignment or large field ranges, provided that the Kähler moduli can be stabilized at special values of the volume.
