New results on the harmonic index and its generalizations Articles uri icon

publication date

  • January 2017

start page

  • 387

end page

  • 404


  • 2


  • 78

International Standard Serial Number (ISSN)

  • 0340-6253


  • In this paper we obtain new inequalities involving the harmonic index and the(general) sum-connectivity index, and characterize graphs extremal with respect tothem. In particular, we improve and generalize some known inequalities and werelate this indices to other well-known topological indices.


  • harmonic index; (general) sum-connectivity index; (general) zagreb index; vertex degree based topological indices