Properties of Laplacian Eigenvalues of Some Bicyclic and Tricyclic Graphs

نویسندگان

1 Department of Mathematics‎, ‎Abbottabad University of Science \& Technology‎, ‎Havelian‎, ‎KPK‎, ‎Pakistan

2 Department of Mathematics‎, ‎Abbottabad University of Science \& Technology‎, ‎Havelian‎, ‎KPK‎, ‎Pakistan

3 Department of Mathematics‎, ‎Abbottabad University of Science \& Technology‎, ‎Havelian‎, ‎KPK‎, ‎Pakistan

4 Department of Mathematics‎, ‎Abbottabad University of Science \& Technology‎, ‎Havelian‎, ‎KPK‎, ‎Pakistan

doi
10.22052/ijmc.2025.256371.1984
چکیده

‎The Laplacian energy (LE) and the Laplacian energy-like (LEL) have recently been proposed based on molecular graph analogues of the total $\pi$-electron energy E‎. ‎Both energies have been widely studied recently because of their wide range of applications‎. ‎In the present work‎, ‎exact expressions of the Laplacian energy and the Laplacian-like invariants of bicyclic and tricyclic molecular graphs in terms of their orders have been obtained‎. ‎We also compute these expressions for the complements of these classes of graphs‎. ‎It is shown that LEL is strictly less than LE for these classes of molecular graphs‎, ‎but for their complements the inequality is the opposite‎.