A Lower Bound for the Max Entropy Algorithm for TSP

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Jin, Billy, Klein, Nathan, Williamson, David P.
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912618985291776
author Jin, Billy
Klein, Nathan
Williamson, David P.
author_facet Jin, Billy
Klein, Nathan
Williamson, David P.
contents One of the most famous conjectures in combinatorial optimization is the four-thirds conjecture, which states that the integrality gap of the subtour LP relaxation of the TSP is equal to $\frac43$. For 40 years, the best known upper bound was 1.5, due to Wolsey (1980). Recently, Karlin, Klein, and Oveis Gharan (2022) showed that the max entropy algorithm for the TSP gives an improved bound of $1.5 - 10^{-36}$. In this paper, we show that the approximation ratio of the max entropy algorithm is at least 1.375, even for graphic TSP. Thus the max entropy algorithm does not appear to be the algorithm that will ultimately resolve the four-thirds conjecture in the affirmative, should that be possible.
format Preprint
id arxiv_https___arxiv_org_abs_2311_01950
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A Lower Bound for the Max Entropy Algorithm for TSP
Jin, Billy
Klein, Nathan
Williamson, David P.
Data Structures and Algorithms
Combinatorics
One of the most famous conjectures in combinatorial optimization is the four-thirds conjecture, which states that the integrality gap of the subtour LP relaxation of the TSP is equal to $\frac43$. For 40 years, the best known upper bound was 1.5, due to Wolsey (1980). Recently, Karlin, Klein, and Oveis Gharan (2022) showed that the max entropy algorithm for the TSP gives an improved bound of $1.5 - 10^{-36}$. In this paper, we show that the approximation ratio of the max entropy algorithm is at least 1.375, even for graphic TSP. Thus the max entropy algorithm does not appear to be the algorithm that will ultimately resolve the four-thirds conjecture in the affirmative, should that be possible.
title A Lower Bound for the Max Entropy Algorithm for TSP
topic Data Structures and Algorithms
Combinatorics
url https://arxiv.org/abs/2311.01950