Computing tree decompositions with small independence number

C Dallard, FV Fomin, PA Golovach, T Korhonen… - arXiv preprint arXiv …, 2022 - arxiv.org
The independence number of a tree decomposition is the maximum of the independence
numbers of the subgraphs induced by its bags. The tree-independence number of a graph is …

Subexponential Parameterized Algorithms on Disk Graphs (Extended Abstract)∗

D Lokshtanov, F Panolan, S Saurabh, J Xue… - Proceedings of the 2022 …, 2022 - SIAM
One of the most celebrated results in Parameterized Complexity is the Bidimensionality
theory of Demaine et al.[J. ACM, 2005], which has yielded, over the past two decades …

Fast static and dynamic approximation algorithms for geometric optimization problems: Piercing, independent set, vertex cover, and matching

S Bhore, TM Chan - Proceedings of the 2025 Annual ACM-SIAM …, 2025 - SIAM
We develop simple and general techniques to obtain faster (near-linear time) static
approximation algorithms, as well as efficient dynamic data structures, for four fundamental …

Sparse outerstring graphs have logarithmic treewidth

S An, E Oh, J Xue - arXiv preprint arXiv:2406.17424, 2024 - arxiv.org
An outerstring graph is the intersection graph of curves lying inside a disk with one endpoint
on the boundary of the disk. We show that an outerstring graph with $ n $ vertices has …

An ETH-tight exact algorithm for Euclidean TSP

M De Berg, HL Bodlaender… - 2018 IEEE 59th …, 2018 - ieeexplore.ieee.org
We study exact algorithms for Euclidean TSP in R d. In the early 1990s algorithms with n O
(√ n) running time were presented for the planar case, and some years later an algorithm …

A framework for approximation schemes on disk graphs

D Lokshtanov, F Panolan, S Saurabh, J Xue… - Proceedings of the 2023 …, 2023 - SIAM
We initiate a systematic study of approximation schemes for fundamental optimization
problems on disk graphs, a common generalization of both planar graphs and unit-disk …

Clique-based separators for geometric intersection graphs

M de Berg, S Kisfaludi-Bak, M Monemizadeh… - Algorithmica, 2023 - Springer
Let F be a set of n objects in the plane and let G×(F) be its intersection graph. A balanced
clique-based separator of G×(F) is a set S consisting of cliques whose removal partitions …

Bipartizing (pseudo-) disk graphs: Approximation with a ratio better than 3

D Lokshtanov, F Panolan, S Saurabh, J Xue… - arXiv preprint arXiv …, 2024 - arxiv.org
In a disk graph, every vertex corresponds to a disk in $\mathbb {R}^ 2$ and two vertices are
connected by an edge whenever the two corresponding disks intersect. Disk graphs form an …

A gap-ETH-tight approximation scheme for Euclidean TSP

S Kisfaludi-Bak, J Nederlof… - 2021 IEEE 62nd Annual …, 2022 - ieeexplore.ieee.org
We revisit the classic task of finding the shortest tour of n, points in d-dimensional Euclidean
space, for any fixed constant d\geqslant2. We determine the optimal dependence on ε in the …

[PDF][PDF] Inapproximability of graph width parameters under small set expansion hypothesis

T Fujita - 2024 - researchgate.net
Research in graph theory remains essential for driving progress in both scientific and
technological fields. Within this area, studies on graph algorithms and those leveraging …