tailieunhanh - Báo cáo toán học: "All regular multigraphs of even order and high degree are 1-factorable"

Tuyển tập các báo cáo nghiên cứu khoa học ngành toán học tạp chí toán học quốc tế đề tài: All regular multigraphs of even order and high degree are 1-factorable. | All regular multigraphs of even order and high degree are 1-factorable Michael J. Plantholt Shailesh K. Tipnis Department of Mathematics Illinois State University Normal IL 61790-4520 USA mikep@ tipnis@ Submitted March 13 2001 Accepted December 8 2001. Mathematical Reviews Subject Classification 2000 05C15 05C70. Abstract Plantholt and Tipnis 1991 proved that for any even integer r a regular multigraph G with even order n multiplicity p G r and degree high relative to n and r is 1-factorable. Here we extend this result to include the case when r is any odd integer. Haggkvist and Perkovic and Reed 1997 proved that the One-factorization Conjecture for simple graphs is asymptotically true. Our techniques yield an extension of this asymptotic result on simple graphs to a corresponding asymptotic result on multigraphs. 1 Introduction Let G be a multigraph with vertex set V G and edge set E G . We denote the maximum degree of G by A G the minimum degree of G by 8 G and the multiplicity of G that is the maximum number of parallel edges between any pair of vertices of G by ụ G . G is said to be simple if p G 1. We say that G is 1-factorable if the edges of G can be partitioned into 1-factors of G. We denote by simp G the simple graph underlying G . simp G is the graph obtained by replacing all edges of G with multiplicity greater than one by single edges. In this paper a decomposition of G into edge-disjoint subgraphs Hi H2 . Hk of G means a partition of E G into the union of the edge sets of Hl H2 . Hk and we abuse the notation and write G Hl u H2 u . u Hk instead of E G E Hl u E H2 u . u E Hk . The reader is referred to Bondy and Murty 2 for all terminology undefined in this paper. The following long-standing conjecture whose THE ELECTRONIC JOURNAL OF COMBINATORICS 8 2001 R41 1 origin is unclear claims that any regular simple graph of even order and with degree at least half the number of vertices is 1-factorizable see 10 . .

TÀI LIỆU LIÊN QUAN
TỪ KHÓA LIÊN QUAN
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.