Resilient Broadcasting via Independent Spanning-Trees

• Applicant: Professor Dr. Jens M. Schmidt
• Subject Area: Theoretical Computer Science
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 401348462

A classic theoretical measure for the resilience of a communication network is its edge-connectivity. However, for some network problems, this measure is not known to be suitable at all. In resilient broadcasting, for example, one prescribed vertex r communicates with every other vertex through a set of spanning trees such that, for every vertex v, the paths from r to v in these spanning trees are edge-disjoint (such trees are called independent). But it is unknown how exactly the maximal number of independent spanning trees in a network relate to its edge-connectivity, and nothing more is known for the analogous question regarding vertex-failures or for the complexity of finding such independent spanning trees.In fact, the long-standing Edge-Independent Spanning Tree Conjecture in graph theory states that every k-edge-connected network contains k independent spanning trees. A proof of this conjecture would not only characterize the networks in which resilient broadcasting is possible, but arguably also deliver the structural insights that are necessary for the compact design of such networks and for efficient routing schemes in these. Although there is recent structural and algorithmic progress on this conjecture for small k (in which case the conjecture is true), a generalization to higher k was not achieved so far.This project aims at attacking the Edge-Independent Spanning Tree Conjecture for higher k, using the recently proposed structures. We will use graph-theoretic methods in order to search for the right generalization to higher k but also computer-assisted algorithms to support this search.

• DFG Programme: Research Grants