{ "id": "1406.1554", "version": "v2", "published": "2014-06-06T01:38:06.000Z", "updated": "2014-07-18T06:10:45.000Z", "title": "A note on nowhere-zero 3-flow and Z_3-connectivity", "authors": [ "Fuyuan Chen", "Bo Ning" ], "comment": "10 pages. Typos corrected", "categories": [ "math.CO" ], "abstract": "There are many major open problems in integer flow theory, such as Tutte's 3-flow conjecture that every 4-edge-connected graph admits a nowhere-zero 3-flow, Jaeger et al.'s conjecture that every 5-edge-connected graph is $Z_3$-connected and Kochol's conjecture that every bridgeless graph with at most three 3-edge-cuts admits a nowhere-zero 3-flow (an equivalent version of 3-flow conjecture). Thomassen proved that every 8-edge-connected graph is $Z_3$-connected and therefore admits a nowhere-zero 3-flow. Furthermore, Lov$\\acute{a}$sz, Thomassen, Wu and Zhang improved Thomassen's result to 6-edge-connected graphs. In this paper, we prove that: (1) Every 4-edge-connected graph with at most seven 5-edge-cuts admits a nowhere-zero 3-flow. (2) Every bridgeless graph containing no 5-edge-cuts but at most three 3-edge-cuts admits a nowhere-zero 3-flow. (3) Every 5-edge-connected graph with at most five 5-edge-cuts is $Z_3$-connected. Our main theorems are partial results to Tutte's 3-flow conjecture, Kochol's conjecture and Jaeger et al.'s conjecture, respectively.", "revisions": [ { "version": "v2", "updated": "2014-07-18T06:10:45.000Z" } ], "analyses": { "subjects": [ "05C21", "05C40" ], "keywords": [ "nowhere-zero", "kochols conjecture", "major open problems", "integer flow theory", "bridgeless graph" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1406.1554C" } } }