Abstract

Wilson (Proceedings of the twenty-eight annual acm symposium on the theory of computing, pp. 296–303, 1996) in the 1990s described a simple and efficient algorithm based on loop-erased random walks to sample uniform spanning trees and more generally weighted trees or forests spanning a given graph. This algorithm provides a powerful tool in analyzing structures on networks and along this line of thinking, in recent works (Avena and Gaudillière in A proof of the transfer-current theorem in absence of reversibility, in Stat. Probab. Lett. 142, 17–22 (2018); Avena and Gaudillière in J Theor Probab, 2017. https://doi.org/10.1007/s10959-017-0771-3; Avena et al. in Approximate and exact solutions of intertwining equations though random spanning forests, 2017. arXiv:1702.05992v1; Avena et al. in Intertwining wavelets or multiresolution analysis on graphs through random forests, 2017. arXiv:1707.04616, to appear in ACHA (2018)) we focused on applications of spanning rooted forests on finite graphs. The resulting main conclusions are reviewed in this paper by collecting related theorems, algorithms, heuristics and numerical experiments. A first foundational part on determinantal structures and efficient sampling procedures is followed by four main applications: (1) a random-walk-based notion of well-distributed points in a graph, (2) a framework to describe metastable-like dynamics in finite settings by means of Markov intertwining dualities, (3) coarse graining schemes for networks and associated processes, (4) wavelets-like pyramidal algorithms for graph signals.

Highlights

  • Networks, Trees and ForestsThe aim of this paper is to survey some recent results [2,3,4,5] on a certain measure on spanning forests of a given graph and its applications within the context of networks analysis

  • G = (V, E, w), where V denotes a finite vertex set of size |V| = n, E stands for a directed edge set seen as a prescribed collection of ordered pairs of vertices {(x, y) ∈ V × V}, and w : V × V → R+ is a weight function, which associates to each ordered pair (x, y) ∈ E a strictly positive weight w(x, y)

  • A rooted spanning forest φ is a subgraph of G without cycle, with V as set of vertices and such that, for each x ∈ V, there is at most one y ∈ V

Read more

Summary

Introduction

The aim of this paper is to survey some recent results [2,3,4,5] on a certain measure on spanning forests of a given graph and its applications within the context of networks analysis. A rooted spanning forest φ is a subgraph of G without cycle, with V as set of vertices and such that, for each x ∈ V, there is at most one y ∈ V such that (x, y) is an edge of φ. Let us notice that the random forest q induces a partition of the graph into trees, and the measure in (1) can be seen on the one hand as a clustering measure similar in spirit to the well-known FK-percolation [19]. The forest q is rooted and the set of roots R( q ) forms an interesting random subset of vertices whose distribution can be explicitly characterized. The presence of the tuning parameter q, controlling size and number of trees, and related efficient sampling algorithms make this measure flexible and suitable for applications

Content of the Paper
Uniform Spanning Tree and a Zoo of Random Combinatorial Models
Basic Objects and Notation
Laplacian Spectrum and Determinantality
Dynamics
Sampling Algorithms
Wilson’s Algorithm
Forests with a Prescribed Number of Roots
Coalescence-Fragmentation Process
Applications
Intertwining and Squeezing
Intertwining in the Literature
The Squeezing Functional
Intertwining and Metastability Without Asymptotics
A Coarse-Graining Algorithm for Metastability
Advantages and Limitations of the Proposed Scheme
Network Coarse-Graining for Signal Processing
Graph Reduction Via Roots Subsampling and the Trace Process
An Experiment
A Metastable Example
Classical Multiresolution
Forest-Multiresolution-Scheme on Arbitrary Networks
Filtering
Quality and Stability of Intertwining Wavelets
Choosing the Downsampling and Concentration Parameters
Comparison with Classical Wavelet Algorithms on the Torus
Findings
A Signal on a Non-regular Graph
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call