度量仿射引力中的轴子虫洞
Axionic Wormholes in Metric-Affine Gravity
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中文总结 AI 辅助
本文在度量仿射引力框架下研究轴子虫洞作为显式U(1)对称性破坏的来源，通过非最小耦合Holst和Nieh-Yan项增强虫洞作用量，缓解轴子质量问题，并扩大可行参数空间以兼容暴胀约束。
中文摘要 AI 辅助
轴子是解决强CP问题的一个有前景的候选者。为了解决这个问题，全局U(1)对称性必须被高精度地保持。然而，众所周知，全局对称性会被量子引力效应明确破坏，从而产生所谓的轴子质量问题。在本文中，我们研究了度量仿射引力中作为显式U(1)破坏来源的轴子虫洞。该框架允许时空挠率和非度量性，这些性质容纳了额外的类曲率和拓扑项，例如Holst项和Nieh-Yan项，而这些项在度量和Palatini形式中是不存在的。我们表明，对这些项的非最小耦合会修改虫洞动力学并增强欧几里得虫洞作用量，从而缓解轴子质量问题。我们还发现，当这些耦合中的两个同时存在时，可行的参数空间会扩大。我们进一步确定了代表性参数区域，在这些区域中，轴子质量问题的缓解与暴胀约束相容。
英文摘要
The axion is a promising candidate for solving the strong CP problem. To solve this problem, the global U(1) symmetry must be preserved to a high degree of accuracy. However, it is well known that global symmetries are explicitly violated by quantum gravity effects, giving rise to what is referred to as the axion quality problem. In this paper, we investigate axionic wormholes as a source of explicit U(1) violation in Metric-Affine Gravity. This framework allows for spacetime torsion and non-metricity, which accommodate additional curvature-like and topological terms, such as the Holst and Nieh--Yan terms, that are absent from the metric and Palatini formalisms. We show that non-minimal couplings to these terms modify the wormhole dynamics and enhance the Euclidean wormhole action, thereby alleviating the axion quality problem. We also find that the viable parameter space is enlarged when two of these couplings are simultaneously present. We further identify representative parameter regions where the alleviation of the axion quality problem is compatible with inflationary constraints.
发表机构
- Hiroshima University（广岛大学）
机构由 AI 辅助整理，请以论文原文为准。
