When Is Degree Enough? Bounds on Degree-Eigenvector Misalignment in Assortative Structured Networks

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Puravankara, Sreerag, Veetil, Vipin P.
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866914401585463296
author Puravankara, Sreerag
Veetil, Vipin P.
author_facet Puravankara, Sreerag
Veetil, Vipin P.
contents A tight alignment between the degree vector and the leading eigenvector arises naturally in networks with neutral degree mixing and the absence of local structures. Many real-world networks, however, violate both conditions. We derive bounds on the divergence between the degree vector and the eigenvector in networks with degree assortativity and local mesoscopic structures such as communities, core-peripheries, and cycles. Our approach is constructive. We design sufficiently general degree-preserving rewiring algorithms that start from a neutral benchmark and monotonically increase assortativity and the strength of local structures, with each step inducing a perturbation of the adjacency matrix. Using the Stewart--Sun Perturbation Bound, together with explicit spectral-norm control of the rewiring steps, we derive upper bounds on the angle between the eigenvector and the degree vector for modest levels of assortativity and local structures. Our analytical bounds delineate regions of `spectral safety' in which a node's degree can be used as a reliable measure of its systemic importance in real-world networks. We also substantiate our analytical bounds with numerical simulations that compute the exact angles of deviation.
format Preprint
id arxiv_https___arxiv_org_abs_2601_00807
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle When Is Degree Enough? Bounds on Degree-Eigenvector Misalignment in Assortative Structured Networks
Puravankara, Sreerag
Veetil, Vipin P.
Social and Information Networks
General Economics
Economics
Theoretical Economics
A tight alignment between the degree vector and the leading eigenvector arises naturally in networks with neutral degree mixing and the absence of local structures. Many real-world networks, however, violate both conditions. We derive bounds on the divergence between the degree vector and the eigenvector in networks with degree assortativity and local mesoscopic structures such as communities, core-peripheries, and cycles. Our approach is constructive. We design sufficiently general degree-preserving rewiring algorithms that start from a neutral benchmark and monotonically increase assortativity and the strength of local structures, with each step inducing a perturbation of the adjacency matrix. Using the Stewart--Sun Perturbation Bound, together with explicit spectral-norm control of the rewiring steps, we derive upper bounds on the angle between the eigenvector and the degree vector for modest levels of assortativity and local structures. Our analytical bounds delineate regions of `spectral safety' in which a node's degree can be used as a reliable measure of its systemic importance in real-world networks. We also substantiate our analytical bounds with numerical simulations that compute the exact angles of deviation.
title When Is Degree Enough? Bounds on Degree-Eigenvector Misalignment in Assortative Structured Networks
topic Social and Information Networks
General Economics
Economics
Theoretical Economics
url https://arxiv.org/abs/2601.00807