• Journal of Applied and Pure Mathematics
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• v.4 no.5_6
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• pp.249-262
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• 2022

Nowadays, it is an important task to find extremal values on any molecular descriptor with respect to different graph parameters. The Sombor index is a novel topological molecular descriptor introduced by Gutman in 2021. The research on determining extremal values for the Sombor index of a graph is very popular recently. In this paper, we present the maximum Sombor index of bicyclic graphs with given matching number. Furthermore, we identify the corresponding extremal bicyclic graphs.

• Kyungpook Mathematical Journal
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• v.54 no.3
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• pp.425-441
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• 2014

In this paper, we first present the properties of the graph which maximize the spectral radius among all graphs with prescribed degree sequence. Using these results, we provide a somewhat simpler method to determine the unicyclic graph with maximum spectral radius among all unicyclic graphs with a given degree sequence. Moreover, we determine the bicyclic graph which has maximum spectral radius among all bicyclic graphs with a given degree sequence.

• The Pure and Applied Mathematics
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• v.27 no.4
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• pp.171-186
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• 2020

Long back in 1972, it was shown that the sum of the squares of vertex degrees and the sum of cubes of vertex degrees of a molecular graph both have large correlations with total 𝜋-electron energy of the molecule. Later on, the sum of squares of vertex degrees was named as first Zagreb index and became one of the most studied molecular graph parameter in the field of chemical graph theory. Whereas, the other sum remained almost unnoticed until recently except for a few occasions. Thus it got the name "forgotten" index or F-index. This paper investigates extremal graphs with respect to F-index among the class of bicyclic graphs with n vertices and k pendant vertices, 0 ≤ k ≤ n - 4. As consequences, we obtain the bicyclic graphs with largest and smallest F-indices.

• Kyungpook Mathematical Journal
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• v.50 no.1
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• pp.109-116
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• 2010

In this paper, we study the signless Laplacian spectral radius of bicyclic graphs with given number of pendant vertices and characterize the extremal graphs.