发表机构
Observatório Nacional; Universidade Federal do Rio Grande do Norte; Instituto Internacional de Física（国家天文台; 北里奥格兰德联邦大学; 国际物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在质量变化中微子宇宙学中，利用pNGB驱动加速并耦合中微子质量，发现可缓解中微子质量张力并产生幻影穿越，且不违反物理条件。
AI 中文摘要
近期对中微子质量之和的宇宙学约束已达到，并在某些分析中低于正常质量排序所隐含的最小值，这表明其可能与中微子振荡测量存在张力。我们研究了在质量变化中微子（MaVaN）宇宙学中这种差异能否得到缓解，其中典型的赝南布-戈德斯通玻色子（pNGB）驱动晚期宇宙加速，并通过指数耦合控制有质量中微子的质量。利用当前的宇宙微波背景、重子声学振荡和Ia型超新星数据，我们重建了中微子质量的演化，并表明宇宙学推断的有效中微子质量可以降至当前正常排序下限以下，同时仍与振荡约束保持一致。同一相互作用产生了一个独特的晚期特征，96%的后验膨胀历史表现出视在幻影分界线$w_{\rm app}=-1$的穿越，穿越红移为$z_{\rm cross}=0.90^{+0.28}_{-0.13}$（68%置信水平）。然而，底层标量场仍保持典型性，满足$w_\phi \geq -1$。因此，我们的结果表明，中微子质量变化可以同时缓解视在中微子质量张力，并产生当前宇宙学数据所偏好的幻影穿越行为，而无需引入幻影场或违反零能量条件。
英文摘要
Recent cosmological constraints on the sum of neutrino masses have reached, and in some analyses fallen below, the minimum value implied by the normal mass ordering, suggesting a possible tension with neutrino-oscillation measurements. We investigate whether this discrepancy can be alleviated in a mass-varying-neutrino (MaVaN) cosmology in which a canonical pseudo-Nambu-Goldstone boson (pNGB) drives late-time cosmic acceleration and controls the masses of massive neutrinos through an exponential coupling. Using current cosmic microwave background, baryon acoustic oscillation, and type Ia supernova data, we reconstruct the neutrino-mass evolution and show that the cosmologically inferred effective neutrino mass can fall below the present-day normal-ordering floor while remaining consistent with oscillation constraints. The same interaction produces a distinctive late-time signature, with 96% of the posterior expansion histories exhibiting a crossing of the apparent phantom divide, $w_{\rm app}=-1$, at $z_{\rm cross}=0.90^{+0.28}_{-0.13}$ at 68% C.L. The underlying scalar field nevertheless remains canonical, with $w_ϕ\geq -1$. Our results therefore show that neutrino mass variation can simultaneously alleviate the apparent neutrino-mass tension and generate the phantom-crossing behavior favored by current cosmological data, without introducing a phantom field or violating the null energy condition.
