Isotropic cosmic birefringence from early dark energy
Isotropic cosmic birefringence from early dark energy
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DOI：
10.1103/physrevd.107.l041302
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发表时间：
2022-09
影响因子：
5
通讯作者：
Kai Murai;Fumihiro Naokawa;T. Namikawa;E. Komatsu
中科院分区：
文献类型：
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作者：
Kai Murai;Fumihiro Naokawa;T. Namikawa;E. Komatsu
在宇宙微波背景（CMB）极化数据的E - B -交叉功率谱中发现了一个诱人的各向同性宇宙双折射的线索，其统计显著性为3\sigma$。通过chen - simons项耦合到CMB光子的伪标量场可以解释这一观测结果。同样的场也可能是早期暗能量（EDE）的原因，这缓解了所谓的哈勃张力。由于EDE场在重组时期发生了显著的变化，将E -模式和B -模式的自动功率谱之差与E -模式的自动功率谱联系起来的传统公式不再有效。通过对偏振光子的玻尔兹曼方程和EDE场动力学的一致求解，我们发现目前青睐的EDE模型参数空间产生了多种形状的EB光谱，可以通过CMB实验进行验证。
A tantalizing hint of isotropic cosmic birefringence has been found in the $E B$ cross-power spectrum of the cosmic microwave background (CMB) polarization data with a statistical significance of $3\sigma$. A pseudoscalar field coupled to the CMB photons via the Chern-Simons term can explain this observation. The same field may also be responsible for early dark energy (EDE), which alleviates the so-called Hubble tension. Since the EDE field evolves significantly during the recombination epoch, the conventional formula that relates $E B$ to the difference between the $E$- and $B$-mode auto-power spectra is no longer valid. Solving the Boltzmann equation for polarized photons and the dynamics of the EDE field consistently, we find that currently favored parameter space of the EDE model yields a variety of shapes of the $EB$ spectrum, which can be tested by CMB experiments.