重复快速射电暴中的时间记忆：暴发源时间因果结构的ε-机重构
Temporal Memory in Repeating Fast Radio Bursts: Epsilon-Machine Reconstruction of Causal Structure in Burst Timing
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中文总结 AI 辅助
研究快速射电暴发射机制，应用ε-机重构分析三个重复FRB等待时间序列，得出FAST的两个源有时间记忆，CHIME的源无记忆，不同源记忆特征不同，该方法为相关物理模型提供了与模型无关的约束。
中文摘要 AI 辅助
快速射电暴（FRB）的发射机制仍然未知。重复FRB的爆发是随机到达还是按结构化序列到达，是该机制的关键限制。我们应用ε-机重构，这是一种来自计算力学的工具，用于推断捕获随机过程中所有预测信息的最小模型。应用于三个重复FRB（FAST的FRB~20121102A和FRB~20201124A；CHIME的FRB~20220912A）的等待时间序列，该方法得出统计复杂度\(C_μ\)，即最优预测所需的最小位数。FAST的两个源都携带大约一位的时间记忆（与排列替代相比有显著差异，\(p≤0.01\)；每个源经错误发现率调整后的\(p≤0.028\)），而FRB~20220912A与无记忆发射一致。FRB~20201124A的记忆跨越四个时段的数小时到数天，FRB~20121102A的记忆跨越三十九个时段的数小时到数周，且两个源在时段内均未显示出可辩护的预测记忆。对于FRB~20121102A，这些时段的排序本身具有预测性（时段洗牌\(p = 0.02\)），而FRB~20201124A的信号反映了不同时段之间的差异而非顺序。模拟窗口测试表明，CHIME的短过境观测会抑制FAST数据中的可比结构，使FRB~20220912A的零结果变得模糊。ε-机重构在天体物理瞬变中的首次应用产生了一个与模型无关的限制：这些重复源中至少有两个的爆发不是无记忆的，而是由一个隐藏状态控制，该状态在不同观测时段占据不同的活动率状态，任何可行的物理模型都必须重现这种行为。
英文摘要
The emission mechanism of fast radio bursts (FRBs) remains unknown. Whether the bursts from a repeating FRB arrive at random or in a structured sequence is a key constraint on that mechanism. We apply $\varepsilon$-machine reconstruction, a tool from computational mechanics that infers the minimal model capturing all predictive information in a stochastic process. Applied to the waiting-time sequences of three repeating FRBs (FRB~20121102A and FRB~20201124A from FAST; FRB~20220912A from CHIME), the method yields the statistical complexity $C_μ$, the minimum number of bits required for optimal prediction. Both FAST sources carry roughly one bit of temporal memory (significant against permutation surrogates, $p \leq 0.01$; per-source false-discovery-rate-adjusted $p \leq 0.028$), while FRB~20220912A is consistent with memoryless emission. FRB~20201124A's memory spans hours-to-days across four sessions, FRB~20121102A's spans hours-to-weeks across thirty-nine, and neither source shows defensible within-session predictive memory. For FRB~20121102A the ordering of those sessions is itself predictive (session-shuffle $p = 0.02$), whereas FRB~20201124A's signal reflects the contrast between heterogeneous sessions rather than their order. A simulated windowing test shows that CHIME's short transit observations would suppress comparable structure in the FAST data, leaving FRB~20220912A's null result ambiguous. This first application of $\varepsilon$-machine reconstruction to astrophysical transients yields a model-independent constraint: the bursting of at least two of these repeaters is not memoryless, but is governed by a hidden state that occupies distinct activity-rate regimes varying across observing sessions, behaviour that any viable physical model must reproduce.
