Flows on flow-admissible signed graphs
WebMar 15, 2024 · The flow number of a signed graph (G, Σ) is the smallest positive integer k such that (G, Σ) admits a nowhere-zero integer k-flow.In 1983, Bouchet (JCTB) conjectured that every flow-admissible signed graph has flow number at most 6. This conjecture remains open for general signed graphs even for signed planar graphs.A Halin graph … WebMay 1, 2024 · Abstract. In 1983, Bouchet proposed a conjecture that every flow-admissible signed graph admits a nowhere-zero 6-flow. Bouchet himself proved that such signed …
Flows on flow-admissible signed graphs
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WebThe concept of integer flows on signed graphs naturally comes from the study of graphs embedded on nonorientable surfaces, where nowhere‐zero flow emerges as the dual notion to local tension. In 1983, Bouchet [2] proposed the following conjecture. Conjecture 1.2 (Bouchet [2]). Every flow‐admissible signed graph admits a nowhere‐zero 6‐flow. WebSep 1, 2024 · Let (G, σ) be a 2-edge-connected flow-admissible signed graph. In this paper, we prove that (G, ... Bouchet A Nowhere-zero integral flows on a bidirected …
WebA signed graph G is flow-admissible if it admits a k-NZF for some positive integer k. Bouchet [2] characterized all flow-admissible signed graphs as follows. Proposition 2.2. ([2]) A connected signed graph G is flow-admissible if and only if ǫ(G) 6= 1 and there is no cut-edge b such that G −b has a balanced component. WebBouchet conjectured in 1983 that every flow-admissible signed graph admits a nowhere-zero 6-flow which is equivalent to the restriction to cubic signed graphs. In this paper, we proved that every flow-admissible 3-edge-colorable cubic …
WebApr 17, 2024 · Recently, Rollová et al proved that every flow-admissible signed cubic graph with two negative edges admits a nowhere-zero 7-flow, and admits a nowhere … WebAug 29, 2024 · Many basic properties in Tutte's flow theory for unsigned graphs do not have their counterparts for signed graphs. However, signed graphs without long barbells in many ways behave like unsigned graphs from the point view of flows. In this paper, we study whether some basic properties in Tutte's flow theory remain valid for …
WebApr 27, 2024 · This motivates us to study how to convert modulo flows into integer-valued flows for signed graphs. In this paper, we generalize some early results by Xu and Zhang (Discrete Math.~299, 2005), Schubert and Steffen (European J. Combin.~48, 2015), and Zhu (J. Combin. Theory Ser. B~112, 2015), and show that, for signed graphs, every …
WebMany basic properties in Tutte's flow theory for unsigned graphs do not have their counterparts for signed graphs. However, signed graphs without long barbells in many ways behave like unsigned graphs from the point view of flows. In this paper, we study whether some basic properties in Tutte's flow theory remain valid for this family of … songs with hoping in the titleWebGraphs or signed graphs considered in this paper are finite and may have multiple edges or loops. For terminology and notations not defined here we follow [1,4,11]. In 1983, … songs with hummingWebThis paper studies the fundamental relations among integer flows, modulo orientations, integer-valued and real-valued circular flows, and monotonicity of flows in signed … small glass measuring cupsWebAug 28, 2024 · In 1983, Bouchet proposed a conjecture that every flow-admissible signed graph admits a nowhere-zero $6$-flow. Bouchet himself proved that such signed … songs with hosanna in the titleWebMany basic properties in Tutte's flow theory for unsigned graphs do not have their counterparts for signed graphs. However, signed graphs without long barbells in many ways behave like unsigned graphs from the point view of flows. In this paper, we study whether some basic properties in Tutte's flow theory remain valid for this family of … songs with houston in the lyricsWebThe presented paper studies the flow number $F(G,sigma)$ of flow-admissible signed graphs $(G,sigma)$ with two negative edges. We restrict our study to cubic g songs with house or home in titleWebApr 17, 2024 · Recently, Rollová et al proved that every flow-admissible signed cubic graph with two negative edges admits a nowhere-zero 7-flow, and admits a nowhere … songs with hump in the title