Near-bipartite bricks in which every b-invariant edge is a forcing edge
Abstract
A connected graph is matching covered if it has at least one edge and every edge lies in some perfect matching.Lovász proved that every matching covered graph G can be uniquely decomposed into a list of bricks and braces up to multiple edges. Denote by b(G) the number of bricks in such a decomposition. An edge e of G is removable if G-e is also matching covered; is b-invariant if e is removable and b(G-e)=b(G). Furthermore, an edge e of G is a forcing edge if it lies in precisely one perfect matching of G. Lucchesi and Murty proposed the problem of characterizing bricks, distinct from K_4, \overline{C_6}, and the Petersen graph, in which every b-invariant edge is a forcing edge. In this paper, we solve this problem for near-bipartite bricks by providing a complete characterization.
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BibTeX
@misc{zhang2026nearbipartite,
title = {{Near-bipartite bricks in which every b-invariant edge is a forcing edge}},
author = {Yaxian Zhang and Fuliang Lu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2607.00608},
eprint = {2607.00608},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.00608},
}
RIS
TY - UNPB
TI - Near-bipartite bricks in which every b-invariant edge is a forcing edge
AU - Yaxian Zhang
AU - Fuliang Lu
PY - 2026
DA - 2026/09/12
PB - arXiv
DO - 10.48550/arxiv.2607.00608
UR - https://arxiv.org/abs/2607.00608
AB - A connected graph is matching covered if it has at least one edge and every edge lies in some perfect matching.Lovász proved that every matching covered graph G can be uniquely decomposed into a list of bricks and braces up to multiple edges. Denote by b(G) the number of bricks in such a decomposition. An edge e of G is removable if G-e is also matching covered; is b-invariant if e is removable and b(G-e)=b(G). Furthermore, an edge e of G is a forcing edge if it lies in precisely one perfect matching of G. Lucchesi and Murty proposed the problem of characterizing bricks, distinct from K_4, \overline{C_6}, and the Petersen graph, in which every b-invariant edge is a forcing edge. In this paper, we solve this problem for near-bipartite bricks by providing a complete characterization.
ER -