Abstract

The harmonic index H ( G ) of a graph G is ∑ u v ∈ E ( G ) 2 d ( u ) + d ( v ) , where d ( v ) is the degree of v ∈ V ( G ) . We show that H ( L ( T ) ) > n 4 for any tree T of order n ≥ 3 , which confirm the validity of a conjecture proposed by Zhang and Wu. In addition, the same lower bound holds for a unicyclic graph G of order n . Two relevant conjectures are proposed as well.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.