AI 中文总结
该研究将纳尔逊-巴尔标量用于驱动山顶暴胀，通过线性形变消除畴壁问题，实现了兼具强CP问题解决、暴胀及重子生成等功能的统一宇宙学框架。
AI 中文摘要
纳尔逊-巴尔机制通过自发CP破缺解决强CP问题，但由此产生的CP共轭真空通常会形成稳定的畴壁。我们提出，纳尔逊-巴尔标量本身驱动山顶暴胀，其虚分量的CP对称双势阱形成两个CP破缺谷，暴胀沿其中一个谷进行。由于最低的CP不变脊通常远高于暴胀后的可用能量，两个分支之间的跃迁在能量上无法实现，暴胀后畴壁无法再生。微小的CP守恒线性形变可提高四次山顶暴胀的标量谱指数，产生符合CMB的参数区域。纳尔逊-巴尔部分必然提供通向可见区再加热的通道，当与右手中微子耦合时，还可将自发CP相位传递到轻子区；在允许更高CP破缺能标的扩展中，甚至可实现非热轻子生成。这确立了纳尔逊-巴尔机制的统一宇宙学实现，其中相同的CP破缺动力学既解决强CP问题，又可产生夸克和轻子CP破缺、驱动暴胀与再加热、实现重子生成，同时消除相关的畴壁问题。
英文摘要
The Nelson-Barr mechanism solves the strong CP problem through spontaneous CP violation, but the resulting CP-conjugate vacua generically lead to stable domain walls. We propose that the Nelson-Barr scalar itself drives hilltop inflation. A CP-symmetric double-well potential for its imaginary component forms two CP-breaking valleys, with inflation proceeding along one of them. Since the lowest CP-invariant ridge is generically much higher than the energy available after inflation, transitions between the two branches are energetically inaccessible, and the domain walls cannot be regenerated after inflation. A small CP-preserving linear deformation raises the scalar spectral index of quartic hilltop inflation and yields CMB-compatible parameter regions. The Nelson-Barr sector necessarily provides a portal to visible-sector reheating. When coupled to right-handed neutrinos, it can also transmit the spontaneous CP phase to the lepton sector and, in an extension that allows a higher CP-breaking scale, even realize nonthermal leptogenesis. This establishes a unified cosmological realization of the Nelson--Barr mechanism in which the same CP-breaking dynamics solves the strong CP problem, can generate quark and lepton CP violation, drives inflation and reheating, and enables baryogenesis, while simultaneously eliminating the associated domain-wall problem.
Comments12 pages, 1 figure
