Limiting Behavior of Degree-Degree Metrics under Local Convergence in Probability
Andrei-Eugeniu Patularu, Pim van der Hoorn
TL;DR
This work studies the limiting behavior of degree-degree metrics under local convergence in probability for sequences of sparse random graphs. It develops general limit theorems for Pearson's $r$, Spearman's $\\rho$, Kendall's $\\tau$, the degree-distance $\\delta$, and the two local measures ANND and ANNR, expressing limits in terms of the limiting rooted graph $(G,o)$ with law $\\mu$ and a uniformly chosen neighbor $V$. The results are then applied to rank-1 inhomogeneous random graphs and random geometric graphs, yielding explicit ANND limits and, in the geometric case, a closed-form limit for Pearson's correlation, highlighting neutral vs. assortative mixing in these models. Overall, the paper provides a unified framework to analyze local-degree correlations across a broad class of sparse graph models with practical implications for network analysis and modeling.
Abstract
This paper investigates the limiting behaviour of degree-degree correlation metrics for sequences of random graphs under a general assumption of local convergence in probability. We establish convergence results for Pearson's correlation coefficient r, Spearman's rho, Kendall's tau, average nearest neighbour degree (ANND), and average nearest neighbour rank (ANNR). Our results explicitly show how the limits of these degree-degree correlation metrics depend on the local structure of the graph. We then apply our general results to study degree-degree correlations in rank-1 inhomogeneous random graphs and random geometric graphs, deriving explicit expressions for ANND in both models and for Pearson's correlation coefficient in the latter one. Keywords: random graphs, degree-degree metrics, neutral mixing
