Abstract
In this work, we study the notion of circular coloring of signed graphs which is a refinement of 0-free 2k-coloring of signed graphs. The main question is that given a positive integer \(\ell \), what is the smallest even value \(f(\ell )\) such that for every signed bipartite (simple) planar graph \((G, \sigma )\) of negative-girth at least \(f(\ell )\), we have \(\chi _c(G, \sigma )\le \frac{2\ell }{\ell -1}\). We answer this question when \(\ell \) is small: \(f(2)=4, f(3)=6\) and \(f(4)=8\). The results fit into the framework of the bipartite analogue of the Jaeger-Zhang conjecture.
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Naserasr, R., Wang, Z. (2021). Circular Coloring of Signed Bipartite Planar Graphs. In: Nešetřil, J., Perarnau, G., Rué, J., Serra, O. (eds) Extended Abstracts EuroComb 2021. Trends in Mathematics(), vol 14. Birkhäuser, Cham. https://doi.org/10.1007/978-3-030-83823-2_33
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DOI: https://doi.org/10.1007/978-3-030-83823-2_33
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