用几何框架解析时序网络演化,揭示隐藏动态与测量误差的深层关联。
Random Dot Product Graphs as Dynamical Systems: Limitations and Opportunities
- 基于主纤维丛建立理论框架,量化潜变量旋转模糊等三大障碍
- 发现可实现切空间维数为 $nd - d(d-1)/2$,且谱间隙决定统计精度
- 提出锚点对齐与UDE管道,可从噪声图序列重构向量场,适合网络动力学研究
能否学习描述时序网络演化的微分方程?我们在随机点积图(RDPGs)中研究这一问题,其中每张网络快照由未知动态下的潜变量生成。我们识别出三个根本障碍:潜变量旋转模糊带来的规范自由度、概率矩阵流形结构带来的可实现性约束,以及谱嵌入导致的轨迹恢复伪影。基于主纤维丛构建几何框架,将不可见动态刻画为反对称生成元,并证明可实现切空间维度为 $nd - d(d-1)/2$。出现全同性二分:多项式动态具有交换生成元、平稳特征向量和平凡全同性,使规范对齐仅依赖统计;拉普拉斯动态满足非交换性条件,产生非平凡全同性,曲率受 $1/(λ_ι+ λ_γ)$ 加权,关联规范敏感性与谱隙。当 $d=2$ 时获得完整受限全同性 $ m{SO}(2)$;$d \≥ 3$ 时一般完整 $ m{SO}(d)$ 全同性仍为猜想。Cramér–Rao下界表明,同一谱隙同时控制曲率、可注入性和费舍尔信息,几何与统计难度不可分割。我们证明可辨识性原理:对称动态无法吸收反对称规范污染,故动态结构可解决规范模糊。通过锚点对齐与UDE流程,我们构造性地实现了从噪声图序列恢复向量场。但有限样本下噪声、规范与动态表达力的交互仍超出现有渐近理论范围,此差距构成开放挑战。
原文摘要 · Abstract (English)
Can we learn the differential equations governing the evolution of a temporal network? We investigate this within Random Dot Product Graphs (RDPGs), where each network snapshot is generated from latent positions evolving under unknown dynamics. We identify three fundamental obstructions: gauge freedom from rotational ambiguity in latent positions, realizability constraints from the manifold structure of the probability matrix, and trajectory recovery artifacts from spectral embedding. We develop a geometric framework based on principal fiber bundles that formalizes these obstructions. We characterize invisible dynamics as exactly the skew-symmetric generators, and show the realizable tangent space has dimension $nd - d(d-1)/2$. An holonomy dichotomy emerges: polynomial dynamics have commuting generators, stationary eigenvectors, and trivial holonomy, making gauge alignment purely statistical; Laplacian dynamics satisfy a non-commutativity criterion producing nontrivial holonomy, with curvature weighted by $1/(λ_ι+ λ_γ)$ linking gauge sensitivity to the spectral gap. In $d=2$ this yields full restricted holonomy $\mathrm{SO}(2)$; for $d \ge 3$ generic full $\mathrm{SO}(d)$ remains conjectural. Cram'er--Rao lower bounds reveal that the same spectral gap controlling curvature and injectivity simultaneously controls Fisher information, so geometric and statistical difficulty are inextricable. We prove an identifiability principle: symmetric dynamics cannot absorb skew-symmetric gauge contamination, so dynamics structure can resolve gauge ambiguity. We demonstrate this constructively with anchor-based alignment and a UDE pipeline recovering vector fields from noisy graph sequences. Yet finite-sample interactions between noise, gauge, and dynamics expressiveness remain beyond the asymptotic theory. We frame this gap as an open challenge.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。