Let G be chosen uniformly at random from the set G G r, n of r-regular graphs w x ลฝ . with vertex set n . We describe polynomial time algorithms that whp i find a ลฝ . Hamilton cycle in G, and ii approximately count the number of Hamilton cycles in G.
Random Matchings Which Induce Hamilton Cycles and Hamiltonian Decompositions of Random Regular Graphs
โ Scribed by Jeong Han Kim; Nicholas C. Wormald
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 215 KB
- Volume
- 81
- Category
- Article
- ISSN
- 0095-8956
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โฆ Synopsis
Select four perfect matchings of 2n vertices, independently at random. We find the asymptotic probability that each of the first and second matchings forms a Hamilton cycle with each of the third and fourth. This is generalised to embrace any fixed number of perfect matchings, where a prescribed set of pairs of matchings must each produce Hamilton cycles (with suitable restrictions on the prescribed set of pairs). We also show how the result with four matchings implies that a random d-regular graph for fixed even d 4 asymptotically almost surely decomposes into dร2 Hamilton cycles. This completes a general result on the edge-decomposition of a random regular graph into regular spanning subgraphs of given degrees together with Hamilton cycles and verifies conjectures of Janson and of Robinson and Wormald.
๐ SIMILAR VOLUMES
Let G n,m,k denote the space of simple graphs with n vertices, m edges, and minimum degree at least k, each graph G being equiprobable. Let G have property A k , if G contains (k -1)/2 edge disjoint Hamilton cycles, and, if k is even, a further edge disjoint matching of size n/2 . We prove that, for