发表机构
Indian Institute of Technology Gandhinagar（印度理工学院甘地纳加尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究以GW250114的直接波为探针，构建回声模板搜寻奇异致密天体的视界反射率，未发现回声证据并给出90%可信边界，实现了对黑洞视界反射率的直接测试。
AI 中文摘要
测试天体物理黑洞的视界性质是引力波天文学的核心目标。近期在GW250114中识别出的直接波（Direct Wave，DW）是一种瞬态非准正则模式分量，为近视界物理提供了新的探测手段。尽管目前尚不清楚DW本身是否携带视界信息，但我们证明其可用于对视界反射率进行新颖的零假设检验。若引力波事件的残余天体是具有部分反射表面的奇异致密天体（Exotic Compact Object，ECO），则向内 plunge 辐射会被反射并通过引力势垒泄漏返回，产生延迟的DW回声，其振幅由表面反射率（|ℛₛ|）决定。我们构建了对应回声模板，以观测到的DW为归一化基准，并在经准正则模式滤波的数据中搜寻该回声。结果未发现回声存在的证据（lnℬ=-2.9），并得到90%可信区间的边界：对于表面位于假想视界外0.1Mf至普朗克长度范围内的情况，|ℛₛ|<0.06，对应反射能量占比低于0.4%。因此，我们的方法将瞬态 ringdown 信号转化为对视界反射率的直接测试。
英文摘要
Testing the horizon properties of astrophysical black holes is a central goal of gravitational-wave astronomy. The recently identified Direct Wave (DW), a prompt non-quasinormal component of GW250114, provides a new probe of near-horizon physics. While it remains unclear whether the DW itself carries horizon information, we show that it enables a novel null test of horizon reflectivity. If the remnant is an exotic compact object (ECO) with a partially reflecting surface, inward plunge radiation is reflected and leaks back through the gravitational potential barrier, producing a delayed DW echo whose amplitude is set by the surface reflectivity ($|\mathcal{R}_s|$). We construct the corresponding echo template, normalized by the observed DW, and search for it in quasinormal-mode-filtered data. We find no evidence for an echo ($\ln\mathcal{B}=-2.9$) and obtain the 90\% credible bound $|\mathcal{R}_s|<0.06$, corresponding to a reflected energy fraction below $0.4\%$, for surfaces from $0.1\, M_f$ to a Planck length from the would-be horizon. Our method thus turns the prompt ringdown signal into a direct test of horizon reflectivity.
