
Proof of the 1-Factorization and Hamilton Decomposition Conjectures
American Mathematical Society (Publisher)
Will be published approx. on 30. October 2016
Book
Paperback/Softback
164 pages
978-1-4704-2025-3 (ISBN)
Description
In this paper the authors prove the following results (via a unified approach) for all sufficiently large n:
(i) [1-factorization conjecture] Suppose that n is even and D?2?n/4??1. Then every D-regular graph G on n vertices has a decomposition into perfect matchings. Equivalently, ?'(G)=D.
(ii) [Hamilton decomposition conjecture] Suppose that D??n/2?. Then every D-regular graph G on n vertices has a decomposition into Hamilton cycles and at most one perfect matching.
(iii) [Optimal packings of Hamilton cycles] Suppose that G is a graph on n vertices with minimum degree ??n/2. Then G contains at least regeven (n,?)/2?(n?2)/8 edge-disjoint Hamilton cycles. Here regeven (n,?) denotes the degree of the largest even-regular spanning subgraph one can guarantee in a graph on n vertices with minimum degree ?.
(i) was first explicitly stated by Chetwynd and Hilton. (ii) and the special case ?=?n/2?of (iii) answer questions of Nash-Williams from 1970. All of the above bounds are best possible.
(i) [1-factorization conjecture] Suppose that n is even and D?2?n/4??1. Then every D-regular graph G on n vertices has a decomposition into perfect matchings. Equivalently, ?'(G)=D.
(ii) [Hamilton decomposition conjecture] Suppose that D??n/2?. Then every D-regular graph G on n vertices has a decomposition into Hamilton cycles and at most one perfect matching.
(iii) [Optimal packings of Hamilton cycles] Suppose that G is a graph on n vertices with minimum degree ??n/2. Then G contains at least regeven (n,?)/2?(n?2)/8 edge-disjoint Hamilton cycles. Here regeven (n,?) denotes the degree of the largest even-regular spanning subgraph one can guarantee in a graph on n vertices with minimum degree ?.
(i) was first explicitly stated by Chetwynd and Hilton. (ii) and the special case ?=?n/2?of (iii) answer questions of Nash-Williams from 1970. All of the above bounds are best possible.
More details
Series
Language
English
Place of publication
Providence
United States
Target group
Professional and scholarly
Dimensions
Height: 254 mm
Width: 178 mm
Weight
260 gr
ISBN-13
978-1-4704-2025-3 (9781470420253)
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Schweitzer Classification
Persons
Bela Csaba, University of Szeged, Hungary.
Daniela Kuhn, University of Birmingham, United Kingdom.
Allan Lo, University of Birmingham, United Kingdom.
Deryk Osthus, University of Birmingham, United Kingdom.
Andrew Treglown, University of Birmingham, United Kingdom.
Daniela Kuhn, University of Birmingham, United Kingdom.
Allan Lo, University of Birmingham, United Kingdom.
Deryk Osthus, University of Birmingham, United Kingdom.
Andrew Treglown, University of Birmingham, United Kingdom.
Content
Introduction
The two cliques case
Exceptional systems for the two cliques case
The bipartite case
Approximate decompositions
Bibliography
The two cliques case
Exceptional systems for the two cliques case
The bipartite case
Approximate decompositions
Bibliography