On Weighted Arboricity: Conductance-Resistance Bounds and Monoid Structure
Authors
Rowan Moxley
Abstract
We study a conductance-weighted arboricity for a finite simple undirected graph with a conductance assignment : This functional reduces to the classical Nash--Williams identity when , is isomorphism invariant, monotone under subgraphs and edge additions, positively homogeneous, and convex. We prove sharp global bounds with attainment by some connected subgraph. On the analytic side, we introduce a local variant and derive conductance--resistance inequalities using effective resistances in the ambient network. If denotes the effective resistance between the endpoints of in , we show that every connected satisfies which in turn yields the upper bound and hence an explicit effective resistance-based upper bound on . On the structural side, we describe the algebraic behavior of . We show that under edge-disjoint union, behaves as a max invariant: for a finite disjoint union of weighted graphs one has . In particular, disjoint union induces a commutative idempotent monoid structure at the level of isomorphism classes, with idempotent with respect to this operation. We also provide a computational exhibit on the hypercube family , including random conductance sampling, illustrating numerical evaluation of the resulting resistance-based bound.