Title
A Simply Exponential Upper Bound on the Maximum Number of Stable Matchings.
Abstract
Stable matching is a classical combinatorial problem that has been the subject of intense theoretical and empirical study since its introduction in 1962 in a seminal paper by Gale and Shapley. In this paper, we provide a new upper bound on f(n), the maximum number of stable matchings that a stable matching instance with n men and n women can have. It has been a long-standing open problem to understand the asymptotic behavior of f(n) as n→∞, first posed by Donald Knuth in the 1970s. Until now the best lower bound was approximately 2.28n, and the best upper bound was 2nlogn− O(n). In this paper, we show that for all n, f(n) ≤ cn for some universal constant c. This matches the lower bound up to the base of the exponent. Our proof is based on a reduction to counting the number of downsets of a family of posets that we call “mixing”. The latter might be of independent interest.
Year
DOI
Venue
2018
10.1145/3188745.3188848
STOC '18: Symposium on Theory of Computing Los Angeles CA USA June, 2018
Keywords
DocType
Volume
stable matching,stable marriage problem,counting,downset,poset
Conference
abs/1711.01032
ISSN
ISBN
Citations 
0737-8017
978-1-4503-5559-9
1
PageRank 
References 
Authors
0.35
9
3
Name
Order
Citations
PageRank
Anna R. Karlin14429646.72
Shayan Oveis Gharan232326.63
Robbie Weber320.71