Observation of high energy cosmic neutrinos by ICECUBE has ushered in a new era in exploring both cosmos and new physics beyond the Standard Model (SM). In the standard picture, although mostly ν_μ and ν_e are produced in the source, oscillation will produce ν_τ en route. Certain beyond SM scenarios, like interaction with ultralight DM can alter this picture. Thus, the flavor composition of the cosmic neutrino flux can open up the possibility of exploring certain beyond the SM scenarios that are inaccessible otherwise. We show that the τ flavor holds a special place among the neutrino flavors in elucidating new physics. Interpreting the two anomalous events observed by ANITA as ν_τ events makes the tau flavor even more intriguing. We study how the detection of the two tau events by ICECUBE constrains the interaction of the neutrinos with ultralight dark matter and discuss the implications of this interaction for even higher energy cosmic neutrinos detectable by future radio telescopes such as ARA, ARIANNA and GRAND. We also revisit the 3 + 1 neutrino scheme as a solution to the two anomalous ANITA events and clarify a misconception that exists in the literature about the evolution of high energy neutrinos in matter within the 3 + 1 scheme with a possibility of scattering off nuclei. We show that the existing bounds on the flux of ν_τ with energy of EeV rules out this solution for the ANITA events. We show that the 3 + 1 solution can be saved from both this bound and from the bound on the extra relativistic degrees of freedom in the early universe by turning on the interaction of neutrinos with ultralight dark matter.

ICECUBE 对高能宇宙中微子的观测开启了探索宇宙和超越标准模型 (SM) 的新物理学的新时代。在标准图片中，虽然大部分ν _μ和ν _e是在源中产生的，但振荡会在途中产生ν _τ 。某些超出 SM 的场景，例如与 Ultralight DM 的交互可以改变此画面。因此，宇宙中微子通量的风味成分可以开启探索某些超出 SM 场景的可能性，否则这些场景是无法访问的。我们表明τ风味在阐明新物理的中微子风味中占有特殊的地位。将 ANITA 观察到的两个异常事件解释为ν _τ事件使 tau 的味道更加有趣。我们研究了 ICECUBE 探测到的两个 tau 事件如何限制中微子与超轻暗物质的相互作用，并讨论这种相互作用对未来射电望远镜（如 ARA、ARIANNA 和 GRAND）可探测到的更高能量宇宙中微子的影响。我们还重新审视了 3 + 1 中微子方案，作为对两个异常 ANITA 事件的解决方案，并澄清了文献中存在的关于 3 + 1 方案中物质中高能中微子演化可能会散射原子核的误解。我们证明了ν _τ通量的现有界限EeV 的能量排除了 ANITA 事件的这种解决方案。我们表明，通过打开中微子与超轻暗物质的相互作用，可以从这个界限和早期宇宙中额外相对论自由度的界限中拯救 3 + 1 解。