用演化轴子在$\Lambda$CDM框架下解释宇宙双折射与DESI数据
Interpreting Cosmic Birefringence and DESI Data with Evolving Axion in $Λ$CDM
AI总结：
针对宇宙观测与标准$\Lambda$CDM模型的矛盾，提出基于动力学轴子场的统一框架，可同时解释宇宙双折射与暗能量状态方程偏离，参数自然且契合观测数据。
摘要：
近期宇宙学观测显示，与标准$\Lambda$CDM模型的矛盾日益凸显，包括各向同性宇宙双折射的迹象，以及暗能量状态方程偏离$w=-1$的情况——这一点得到了DESI（暗能量光谱仪）和超新星测量结果的支持。本文指出，即便次主导的能量密度组分也可能引发这类偏离。我们随后提出了一个基于动力学轴子场的统一框架，可同时解释这两种反常现象，是对标准$\Lambda$CDM模型简单且自然的拓展。在我们的方案中，满足$2H_0\lesssim m\lesssim 6H_0$（其中$H_0$为当前哈勃常数）的轴子场会引发CMB（宇宙微波背景）偏振面的非零旋转，并修正当下的暗能量状态方程。该框架通过自然的参数取值就能契合近期观测数据，即便对于衰变常数约为$10^{17}\\,$GeV的弦轴子也同样适用。
英文摘要：
Recent cosmological observations have revealed growing tensions with the standard $Λ$CDM model, including indications of isotropic cosmic birefringence and deviations from $w = -1$ in the dark energy equation of state, as suggested by DESI and supernova measurements. In this paper, we point out that such deviations can arise even from a subdominant energy density component. We then propose a unified framework based on a dynamical axion field that simultaneously accounts for both anomalies, providing a simple and natural extension of the standard $Λ$CDM model. In our scenario, the axion field with $2H_0\lesssim m\lesssim 6H_0$, where $H_0$ is the current Hubble constant, induces a nonzero rotation of the CMB polarization plane and modifies the present-day dark energy equation of state. This framework accommodates recent observational data with natural parameter choices, even for a string axion with a decay constant of order $10^{17}\,$GeV.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
