ScholarWorks@성균관대학교

초록

In our research, we are studying the relationship between the energy and Zagreb indices of a graph. We have proven several results, including: (i) tight lower and upper bounds for the energy of graphs based on their order, size, minimum degree, maximum degree, minimum eigenvalue, Zagreb indices, positive inertia, and negative inertia. We have also characterized the graphs that achieve equalities. (ii) Tight lower and upper bounds for maximum eigenvalue of graphs in terms of their order, size, minimum degree, maximum degree, and Zagreb indices. We have also characterized the graphs that achieve equalities. After conducting observations and computational calculations, we have formulated the conjecture that for a non-singular graph Omega$\Omega$ with order p, size m, and the first Zagreb index M1(Omega)$M_1(\Omega )$, the following should hold: E(Omega)>= M1(Omega)m$\mathcal{E}(\Omega )\ge \frac{M_1(\Omega )}{m}$ and E(Omega)>= M1(Omega)2m+2mp$\mathcal{E}(\Omega )\ge \frac{M_1(\Omega )}{2m}+\frac{2m}{p}$, with both equalities holding iff Omega congruent to Kp$\Omega \cong K_p$. It has been demonstrated that proving the first inequality will validate the second inequality.

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