Reweighted Spectral Partitioning Works: A Simple Algorithm for Vertex Separators in Special Graph Classes

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Spalding-Jamieson, Jack
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909907294355456
author Spalding-Jamieson, Jack
author_facet Spalding-Jamieson, Jack
contents We establish that a simple polynomial-time algorithm that we call reweighted spectral partitioning obtains small 2/3-balanced vertex-separators for a number of graph classes, including $O(\sqrt{n})$-sized separators for planar graphs, $O(\min\{(\log g)^2,\logΔ\}\cdot\sqrt{gn})$-sized separators for genus-$g$ graphs of maximum degree $Δ$, and $O(\min\{\log h,\sqrt{\logΔ}\}(h\log h\log\log h)\sqrt{n})$-sized separators for $K_h$-minor-free graphs of maximum degree $Δ$. To accomplish this, we first obtain a refined form of a Cheeger-style inequality relating the vertex expansion of a graph and the solution to a semidefinite program defined over the graph. Then, to obtain the guarantees for specific graph classes, we derive direct bounds on the value of the semidefinite program. We also obtain several other results of independent interest, including an improved separator theorem for the intersection graphs of $d$-dimensional balls with bounded ply, a new bound on the Fiedler value of genus-$g$ graphs, and a new "spectral" proof of the planar separator theorem.
format Preprint
id arxiv_https___arxiv_org_abs_2506_01228
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Reweighted Spectral Partitioning Works: A Simple Algorithm for Vertex Separators in Special Graph Classes
Spalding-Jamieson, Jack
Data Structures and Algorithms
Computational Geometry
Discrete Mathematics
We establish that a simple polynomial-time algorithm that we call reweighted spectral partitioning obtains small 2/3-balanced vertex-separators for a number of graph classes, including $O(\sqrt{n})$-sized separators for planar graphs, $O(\min\{(\log g)^2,\logΔ\}\cdot\sqrt{gn})$-sized separators for genus-$g$ graphs of maximum degree $Δ$, and $O(\min\{\log h,\sqrt{\logΔ}\}(h\log h\log\log h)\sqrt{n})$-sized separators for $K_h$-minor-free graphs of maximum degree $Δ$. To accomplish this, we first obtain a refined form of a Cheeger-style inequality relating the vertex expansion of a graph and the solution to a semidefinite program defined over the graph. Then, to obtain the guarantees for specific graph classes, we derive direct bounds on the value of the semidefinite program. We also obtain several other results of independent interest, including an improved separator theorem for the intersection graphs of $d$-dimensional balls with bounded ply, a new bound on the Fiedler value of genus-$g$ graphs, and a new "spectral" proof of the planar separator theorem.
title Reweighted Spectral Partitioning Works: A Simple Algorithm for Vertex Separators in Special Graph Classes
topic Data Structures and Algorithms
Computational Geometry
Discrete Mathematics
url https://arxiv.org/abs/2506.01228