Abstract
Let k be an integer with k ≥ 1, and let G be a graph. A k-factor of G is a spanning subgraph F of G such that d F (x) = k for each \({x\in V(G)}\) . Let \({h:E(G)\rightarrow[0,1]}\) be a function. If \({\sum_{e\ni x}h(e)=k}\) holds for each \({x\in V(G)}\) , then we call G[F h ] a fractional k-factor of G with indicator function h, where \({F_h=\{e\in E(G): h(e) >0 \}}\) . A graph G is fractional independent-set-deletable k-factor-critical (in short, fractional ID-k-factor-critical) if G−I has a fractional k-factor for every independent set I of G. In this paper, we prove that if \({\alpha(G)\leq\frac{4k(\delta(G)-k+1)}{k^{2}+6k+1}}\) , then G is fractional ID-k-factor-critical. The result is best possible in some sense.
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References
Lovasz L., Plummer M.D.: Matching Theory. Elsevier, North Holland (1985)
Yuan J.: Independent-set-deletable factor-critical power graphs. Acta Mathematica Scientia Ser. B 26(4), 577–584 (2006)
Chang R., Liu G., Zhu Y.: Degree conditions of fractional ID-k-factor-critical graphs. Bull. Malays. Math. Sci. Soc. 33(3), 355–360 (2010)
Fan H., Liu G., Liu J., Long H.: The existence of even regular factors of regular graphs on the number of cut edges. Acta Mathematica Sinica 26(12), 2305–2312 (2010)
Zhou S.: Independence number, connectivity and (a, b, k)-critical graphs. Discrete Math. 309(12), 4144–4148 (2009)
Zhou S.: Binding numbers and [a, b]-factors excluding a given k-factor. Comptes Rendus Mathematique 349(19–20), 1021–1024 (2011)
Zhou S., Jiang J.: Notes on the binding numbers for (a, b, k)-critical graphs. Bull. Aust. Math. Soc. 76(2), 307–314 (2007)
Liu H., Liu G.: Binding number and minimum degree for the existence of (g, f, n)-critical graphs. J. Appl. Math. Comput. 29(1–2), 207–216 (2009)
Fourtounelli O., Katerinis P.: The existence of k-factors in squares of graphs. Discrete Math. 310(23), 3351–3358 (2010)
Cai J., Liu G.: Stability number and fractional f-factors in graphs. Ars Combinatoria 80, 141–146 (2006)
Liu G., Yu Q., Zhang L.: Maximum fractional factors in graphs. Appl. Math. Lett. 20(12), 1237–1243 (2007)
Zhou S.: A sufficient condition for graphs to be fractional (k, m)-deleted graphs. Appl. Math. Lett. 24(9), 1533–1538 (2011)
Zhou S.: Some new sufficient conditions for graphs to have fractional k-factors. Int. J. Comp. Math. 88(3), 484–490 (2011)
Liu G., Zhang L.: Toughness and the existence of fractional k-factors of graphs. Discrete Math. 308, 1741–1748 (2008)
Liu G., Zhang L.: Fractional (g, f)-factors of graphs. Acta Mathematica Scientia 21(4), 541–545 (2001)
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This research was supported by Natural Science Foundation of the Higher Education Institutions of Jiangsu Province (10KJB110003) and Jiangsu University of Science and Technology (2010SL101J), and was sponsored by Qing Lan Project of Jiangsu Province.
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Zhou, S., Xu, L. & Sun, Z. Independence number and minimum degree for fractional ID-k-factor-critical graphs. Aequat. Math. 84, 71–76 (2012). https://doi.org/10.1007/s00010-012-0121-6
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DOI: https://doi.org/10.1007/s00010-012-0121-6