Local search for weighted tree augmentation and steiner tree

V Traub, R Zenklusen - Proceedings of the 2022 Annual ACM-SIAM …, 2022 - SIAM
We present a technique that allows for improving on some relative greedy procedures by
well-chosen (non-oblivious) local search algorithms. Relative greedy procedures are a …

A better-than-2 approximation for weighted tree augmentation

V Traub, R Zenklusen - 2021 IEEE 62nd Annual Symposium on …, 2022 - ieeexplore.ieee.org
A Better-Than-2 Approximation for Weighted Tree Augmentation Page 1 A Better-Than-2
Approximation for Weighted Tree Augmentation Vera Traub Department of Mathematics ETH …

Bridging the gap between tree and connectivity augmentation: unified and stronger approaches

F Cecchetto, V Traub, R Zenklusen - … of the 53rd Annual ACM SIGACT …, 2021 - dl.acm.org
We consider the Connectivity Augmentation Problem (CAP), a classical problem in the area
of Survivable Network Design. It is about increasing the edge-connectivity of a graph by one …

A (1.5+ ε)-approximation algorithm for weighted connectivity augmentation

V Traub, R Zenklusen - Proceedings of the 55th Annual ACM …, 2023 - dl.acm.org
Connectivity augmentation problems are among the most elementary questions in Network
Design. Many of these problems admit natural 2-approximation algorithms, often through …

Improved approximation for tree augmentation: saving by rewiring

F Grandoni, C Kalaitzis, R Zenklusen - … of the 50th Annual ACM SIGACT …, 2018 - dl.acm.org
The Tree Augmentation Problem (TAP) is a fundamental network design problem in which
we are given a tree and a set of additional edges, also called links. The task is to find a set of …

Breaching the 2-approximation barrier for connectivity augmentation: a reduction to Steiner tree

J Byrka, F Grandoni, AJ Ameli - Proceedings of the 52nd Annual ACM …, 2020 - dl.acm.org
The basic goal of survivable network design is to build a cheap network that maintains the
connectivity between given sets of nodes despite the failure of a few edges/nodes. The …

Improved approximation for two-edge-connectivity

M Garg, F Grandoni, A Jabal Ameli - Proceedings of the 2023 Annual ACM …, 2023 - SIAM
The basic goal of survivable network design is to construct low-cost networks which
preserve a sufficient level of connectivity despite the failure or removal of a few nodes or …

Breaching the 2-approximation barrier for the forest augmentation problem

F Grandoni, AJ Ameli, V Traub - Proceedings of the 54th Annual ACM …, 2022 - dl.acm.org
The basic goal of survivable network design is to build cheap networks that guarantee the
connectivity of certain pairs of nodes despite the failure of a few edges or nodes. A …

Approximating k-edge-connected spanning subgraphs via a near-linear time LP solver

P Chalermsook, CC Huang, D Nanongkai… - arxiv preprint arxiv …, 2022 - arxiv.org
In the $ k $-edge-connected spanning subgraph ($ k $ ECSS) problem, our goal is to
compute a minimum-cost sub-network that is resilient against up to $ k $ link failures: Given …

Flexible Graph Connectivity: Approximating network design problems between 1-and 2-connectivity

D Adjiashvili, F Hommelsheim… - Mathematical Programming, 2022 - Springer
We introduce and study the problem Flexible Graph Connectivity, which in contrast to many
classical connectivity problems features a non-uniform failure model. We distinguish …