Rainbow Matchings: existence and counting

نویسندگان

  • Guillem Perarnau
  • Oriol Serra
چکیده

A perfect matching M in an edge–colored complete bipartite graph Kn,n is rainbow if no pair of edges in M have the same color. We obtain asymptotic enumeration results for the number of rainbow matchings in terms of the maximum number of occurrences of a color. We also consider two natural models of random edge–colored Kn,n and show that, if the number of colors is at least n, then there is whp a random matching. This in particular shows that almost every square matrix of order n in which every entry appears at most n times has a Latin transversal.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Rainbow Matchings and Rainbow Connectedness

Aharoni and Berger conjectured that every collection of n matchings of size n+1 in a bipartite graph contains a rainbow matching of size n. This conjecture is related to several old conjectures of Ryser, Brualdi, and Stein about transversals in Latin squares. There have been many recent partial results about the Aharoni-Berger Conjecture. The conjecture is known to hold when the matchings are m...

متن کامل

On rainbow matchings in bipartite graphs

We present recent results regarding rainbow matchings in bipartite graphs. Using topological methods we address a known conjecture of Stein and show that if Kn,n is partitioned into n sets of size n, then a partial rainbow matching of size 2n/3 exists. We generalize a result of Cameron and Wanless and show that for any n matchings of size n in a bipartite graph with 2n vertices there exists a f...

متن کامل

Abstract—alexey Pokrovskiy

Alexey Pokrovskiy Aharoni and Berger conjectured [1] that every bipartite graph which is the union of n matchings of size n + 1 contains a rainbow matching of size n. This conjecture is related to several old conjectures of Ryser, Brualdi, and Stein about transversals in Latin squares. There have been many recent partial results about the Aharoni-Berger Conjecture. When the matchings have size ...

متن کامل

Counting Matchings with k Unmatched Vertices in Planar Graphs

We consider the problem of counting matchings in planar graphs. While perfect matchings in planar graphs can be counted by a classical polynomial-time algorithm [26, 33, 27], the problem of counting all matchings (possibly containing unmatched vertices, also known as defects) is known to be #P-complete on planar graphs [23]. To interpolate between the hard case of counting matchings and the eas...

متن کامل

Size Conditions for the Existence of Rainbow Matchings

Let f(n, r, k) be the minimal number such that every hypergraph larger than f(n, r, k) contained in ([n] r ) contains a matching of size k, and let g(n, r, k) be the minimal number such that every hypergraph larger than g(n, r, k) contained in the r-partite r-graph [n]r contains a matching of size k. The Erdős-Ko-Rado theorem states that f(n, r, 2) = (n−1 r−1 ) (r ≤ n 2 ) and it is easy to show...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Electronic Notes in Discrete Mathematics

دوره 38  شماره 

صفحات  -

تاریخ انتشار 2011