Spectral extrema of graphs with fixed size: Cycles and complete bipartite graphs
نویسندگان
چکیده
Nikiforov (2002) showed that if G is Kr+1-free then the spectral radius ?(G)?2m(1?1?r), which implies contains C3 ?(G)>m. In this paper, we follow direction in determining subgraphs will be contained ?(G)>f(m), where f(m)?m as m??. We first show ?(G)?m, K2,r+1 unless a star; and either C3+ or C4+ complete bipartite graph, Ct+ denotes graph obtained from Ct by identifying an edge. Secondly, prove ?(G)?12+m?34, pentagon hexagon book; ?(G)>12(k?12)+m+14(k?12)2, for every t?2k+2. end, some related conjectures are provided further research.
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ژورنال
عنوان ژورنال: European Journal of Combinatorics
سال: 2021
ISSN: ['1095-9971', '0195-6698']
DOI: https://doi.org/10.1016/j.ejc.2021.103322