论文标题
通过CMB极化探测轴突样颗粒
Probing Axion-like Particles via CMB Polarization
论文作者
论文摘要
轴状颗粒（ALP）通过ALP-PHOTON耦合旋转光子的线性极化，并将宇宙微波背景（CMB）$ E $ -MODE转换为$ B $ -MODE。我们通过假设ALP $ ϕ $具有二次电位，$ v = m^2ϕ^2/2 $来得出ALP动力学与旋转角度之间的关系。我们计算CMB观察的当前和未来敏感性对Alp-Photon耦合$ G $，可以达到$ G = 4 \ times 10^{ - 21} \，\ Mathrm {gev}^{ - 1} $ for $ 10^{ - 32}} { - 32}}}} 10^{ - 28} \，\ Mathrm {ev} $，并广泛超越了其他质量$ M \ lyseSim 10^{ - 25} \，\ Mathrm {ev} $的其他搜索。我们发现，在先前的研究中忽略了观察者的ALP场的波动可以诱导CMB极化的显着各向同性旋转。各向同性和各向异性旋转的测量值使我们能够在相关数量的范围内（例如ALP质量$ $ $和ALP密度参数$ ω__ϕ $）提出界限。特别是，如果Litebird检测到各向异性旋转，我们将张量与尺度比率的下限作为$ r> 5 \ times 10^{ - 9} $。
Axion-like particles (ALPs) rotate the linear polarization of photons through the ALP-photon coupling and convert the cosmic microwave background (CMB) $E$-mode to the $B$-mode. We derive the relation between the ALP dynamics and the rotation angle by assuming that the ALP $ϕ$ has a quadratic potential, $V=m^2ϕ^2/2$. We compute the current and future sensitivities of CMB observations to the ALP-photon coupling $g$, which can reach $g=4\times 10^{-21}\,\mathrm{GeV}^{-1}$ for $10^{-32}\,\mathrm{eV}\lesssim m\lesssim 10^{-28}\,\mathrm{eV}$ and extensively exceed the other searches for any mass $m\lesssim 10^{-25}\,\mathrm{eV}$. We find that the fluctuation of the ALP field at the observer, which has been neglected in previous studies, can induce significant isotropic rotation of the CMB polarization. The measurements of isotropic and anisotropic rotation allow us to put bounds on relevant quantities such as the ALP mass $m$ and the ALP density parameter $Ω_ϕ$. In particular, if LiteBIRD detects anisotropic rotation, we obtain the lower bound on the tensor-to-scalar ratio as $r > 5 \times 10^{-9}$.
