University of KashanIranian Journal of Mathematical Chemistry2228-648912420211230Extremal Cacti with respect to Sombor index19720811163210.22052/ijmc.2021.243026.1582ENHechaoLiuSchool of Mathematical Sciences, South China Normal University, Guangzhou, 510631, P. R. China0000-0001-7606-4842Journal Article20210821Recently, a novel topological index, Sombor index, was introduced by Gutman, defined as $SO(G)=sumlimits_{uvin E(G)}sqrt{d_{u}^{2}+d_{v}^{2}}$, where $d_{u}$ denotes the degree of vertex $u$. In this paper, we first determine the maximum Sombor index among cacti with $n$ vertices and $t$ cycles, then determine the maximum Sombor index among cacti with perfect matchings. We also characterize corresponding maximum cacti.https://ijmc.kashanu.ac.ir/article_111632_de6f31ed2e636e86763d50333fb73e29.pdfUniversity of KashanIranian Journal of Mathematical Chemistry2228-648912420211230On Sombor Index and some Topological Indices20921511162410.22052/ijmc.2021.243137.1588ENChinglensanaPhanjoubamMathematics department, North-Eastern Hill University, Shillong, IndiaSainkupar MnMawiongDepartment of Basic Sciences and Social Sciences, North Eastern Hill University, Shillong, IndiaJournal Article20210927Gutman recently introduced a new vertex-degree-based topological index called the Sombor index. In this paper, we present some new results relating the Sombor index and some well-studied topological indices: Zagreb indices, forgotten index, harmonic index, (general) sum-connectivity index and symmetric division deg index.https://ijmc.kashanu.ac.ir/article_111624_70eb6680db0a7162341bf37cbe6de294.pdfUniversity of KashanIranian Journal of Mathematical Chemistry2228-648912420211230Topological Indices of a Kind of Altans21722411163310.22052/ijmc.2021.242983.1577ENShimaSalimiDepartment of Mathematics, University of Payame Noor, Tehran, IranAliIranmaneshTarbiat Modares UniversityJournal Article20210803Altans are a class of molecular graphs introduced recently. These graphs are attractive to many chemists and mathematicians. A topological index is a numerical invariant calculated for a description of molecular graphs. In this paper, we compute a few topological indices of Altans such as Wiener index, second Zagreb index, atom-bond connectivity (ABC) index, 〖ABC〗_4 index, etc.https://ijmc.kashanu.ac.ir/article_111633_13328fa0e939453c37f1689da4170b7a.pdfUniversity of KashanIranian Journal of Mathematical Chemistry2228-648912420211230The Randic Index of Trees with given Total Domination Number22523711163510.22052/ijmc.2021.243170.1591ENRoslanHasniSchool of Informatics and Applied Mathematics
Universiti Malaysia Terengganu
UMT TerengganuAyu Ameliatul ShahilahAhmad JamriUMT TerengganuNabeel EzzuldinArifTikrit UniversityFatimah NoorHarunUMT TerengganuJournal Article20211006Randi{'c} index belongs to the most well-known topological indices in chemical graph theory. In this paper, we find upper bound for the Randi{'c} index of trees in terms of the order and the total domination number. The extremal trees are characterized.https://ijmc.kashanu.ac.ir/article_111635_f818385c7fe7f8b5afb3d00ee3bf60a2.pdf