论文标题
延长对称性的轴轴丰度减少
Reduced Axion Abundance from an Extended Symmetry
论文作者
论文摘要
在最近的工作中，我们表明，当Peccei-Quinn（PQ）场耦合到非常轻的标量/s时，可以改变QCD轴的遗物深色物质丰度，从而在早期的宇宙中赋予有效的轴质量动力学。在这项工作中，我们通过引入一个新的扩展对称组来进一步开发该框架，以保护新粒子的质量。我们发现，使用新的全球$ SO（N）$对称性，并具有大$ N $，我们不仅可以说明新标量的轻度，而且可以以技术自然的方式减少Axion Relic的丰度。这打开了大型PQ量表的可能性，包括接近肠道尺度，并且仍然自然产生正确的轴静物丰度。同样，在这些模型中，有效的PQ量表在早期的宇宙中相对较小，因此这可以帮助减轻从通货膨胀中的同化问题。此外，扩展的对称性不是可能与宇宙字符串过度关闭，这意味着形成了具有相对较小丰度的非原始纹理。
In recent work we showed that the relic dark matter abundance of QCD axions can be altered when the Peccei-Quinn (PQ) field is coupled to very light scalar/s, rendering the effective axion mass dynamical in the early universe. In this work we develop this framework further, by introducing a new extended symmetry group to protect the new particles' mass. We find that with a new global $SO(N)$ symmetry, with large $N$, we can not only account for the lightness of the new scalars, but we can reduce the axion relic abundance in a technically natural way. This opens up the possibility of large PQ scales, including approaching the GUT scale, and still naturally producing the correct relic abundance of axions. Also, in these models the effective PQ scale is relatively small in the very early universe, and so this can help towards alleviating the isocurvature problem from inflation. Furthermore, instead of possible over-closure from cosmic strings, the extended symmetry implies the formation of non-topological textures which provide a relatively small abundance.
