A CMB Millikan experiment with cosmic axiverse strings
A CMB Millikan experiment with cosmic axiverse strings
复制标题
DOI：
10.1007/jhep07(2020)138
复制
发表时间：
2019-12
影响因子：
5.4
通讯作者：
P. Agrawal;A. Hook;Junwu Huang
中科院分区：
文献类型：
--
作者：
P. Agrawal;A. Hook;Junwu Huang
我们研究耦合到光子的超光轴离子的轴子弦。超光轴子--复合时比哈勃更轻的轴子--是弦轴的一般预言。这些轴子弦产生cmb光子的独特的量子化偏振旋转，即(αem)。当CMB光通过许多串时，这种偏振旋转将E模转换为B模，并像随机漫步一样累积。数值模拟表明，通过测量CMB B模与E模和T模的关联，最终结果的预期大小完全在当前和未来CMB实验的可及范围内。量子化的偏振旋转角本质上是拓扑性的，可以看作是一个几何相位。它的值只取决于反常系数，与其他细节无关，如轴子衰变常数。通过测量这一自转来测量反常系数将提供有关UV理论的信息，如电荷的量子化和基本电荷单位的值。宇宙中轴子弦的存在只依赖于膨胀后早期宇宙的相变，之后弦网络迅速接近吸引子标度解。如果有更多稳定的拓扑物，如磁区壁，那么重达10−15 eV的轴子将是可以访问的。这些弦的存在也可以通过测量引力透镜类星体系统中不同图像之间的相对偏振旋转角来探测。
We study axion strings of hyperlight axions coupled to photons. Hyperlight axions—axions lighter than Hubble at recombination—are a generic prediction of the string axiverse. These axions strings produce a distinct quantized polarization rotation of CMB photons which is(α em). As the CMB light passes many strings, this polarization rotation converts E-modes to B-modes and adds up like a random walk. Using numerical simulations we show that the expected size of the final result is well within the reach of current and future CMB experiments through the measurement of correlations of CMB B-modes with E-and T-modes. The quantized polarization rotation angle is topological in nature and can be seen as a geometric phase. Its value depends only on the anomaly coefficient and is independent of other details such as the axion decay constant. Measurement of the anomaly coefficient by measuring this rotation will provide information about the UV theory, such as the quantization of electric charge and the value of the fundamental unit of charge. The presence of axion strings in the universe relies only on a phase transition in the early universe after inflation, after which the string network rapidly approaches an attractor scaling solution. If there are additional stable topological objects such as domain walls, axions as heavy as 10− 15 eV would be accessible. The existence of these strings could also be probed by measuring the relative polarization rotation angle between different images in gravitationally lensed quasar systems.