Algebraically grid-like graphs have large tree-width
Combinatorics
2018-02-15 v1
Abstract
By the Grid Minor Theorem of Robertson and Seymour, every graph of sufficiently large tree-width contains a large grid as a minor. Tree-width may therefore be regarded as a measure of 'grid-likeness' of a graph. The grid contains a long cycle on the perimeter, which is the -sum of the rectangles inside. Moreover, the grid distorts the metric of the cycle only by a factor of two. We prove that every graph that resembles the grid in this algebraic sense has large tree-width: Let be integers, a real number and a graph. Suppose that contains a cycle of length at least which is the -sum of cycles of length at most and whose metric is distorted by a factor of at most . Then has tree-width at least .
Keywords
Cite
@article{arxiv.1802.05158,
title = {Algebraically grid-like graphs have large tree-width},
author = {Daniel Weißauer},
journal= {arXiv preprint arXiv:1802.05158},
year = {2018}
}
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6 pages