AI 中文总结
研究额外维度 QCD 轴子在暴胀时量子涨落产生等曲率微扰限制暴胀尺度的问题，提出在翘曲五维模型中的动态抑制机制，可满足 CMB 等曲率界限并允许更高暴胀尺度。
AI 中文摘要
额外维度的 QCD 轴子由弦紧致化很好地推动，并且对质量违反效应有增强的保护。然而，如果在暴胀期间存在，其量子涨落会产生等曲率微扰，强烈限制暴胀尺度。我们在翘曲的五维模型中提出一种动态抑制机制，其中一个胀子 - 场耦合在暴胀期间将场最小值设置在小的膜间分离处，暂时增强有效的四维轴子衰变常数。暴胀后，场最小值移到更大的分离处，恢复标准的 QCD 轴子窗口。在具有 Goldberger - Wise 稳定的翘曲 orbifold GUT 中，这种机制可以满足 CMB 等曲率界限，同时允许比传统暴胀前轴子宇宙学更高的暴胀尺度。
英文摘要
Extra-dimensional QCD axion is well motivated by string compactifications and enjoys enhanced protection against quality-violating effects. If present during inflation, however, its quantum fluctuations generate isocurvature perturbations that strongly constrain the inflationary scale. We propose a dynamical suppression mechanism in warped five-dimensional models, where a radion-inflaton coupling sets the radion minimum at small inter-brane separation during inflation, temporarily enhancing the effective four-dimensional axion decay constant. After inflation, the radion minimum shifts to larger separation, restoring the standard QCD axion window. In a warped orbifold GUT with Goldberger-Wise stabilization, this mechanism can satisfy CMB isocurvature bounds while allowing substantially higher inflationary scales than in conventional pre-inflationary axion cosmology.
Comments11 pages, 3 figures
