Investigation of Atom-Bond Connectivity Indices of Line Graphs Using Subdivision Approach
Mohamad Nazri Husin, Sohail Zafar, R. U. Gobithaasan
Abstract
A topological index is a numerical measure that characterises the whole structure of a graph. Based on vertex degrees, the idea of an atom-bond connectivity <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mfenced open="(" close=")" separators="|"> <a:mrow> <a:mi>A</a:mi> <a:mi>B</a:mi> <a:mi>C</a:mi> </a:mrow> </a:mfenced> </a:math> index was introduced in chemical graph theory. Later, different versions of the ABC index were created, and some of these indices were recently designed. In this paper, we present the edge version of the atom-bond connectivity <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" id="M2"> <f:mfenced open="(" close=")" separators="|"> <f:mrow> <f:mi>A</f:mi> <f:mi>B</f:mi> <f:msub> <f:mrow> <f:mi>C</f:mi> </f:mrow> <f:mrow> <f:mi>e</f:mi> </f:mrow> </f:msub> </f:mrow> </f:mfenced> </f:math> index, edge version of the multiplicative atom-bond connectivity <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" id="M3"> <k:mfenced open="(" close=")" separators="|"> <k:mrow> <k:mi>A</k:mi> <k:mi>B</k:mi> <k:mi>C</k:mi> <k:mi>I</k:mi> <k:msub> <k:mrow> <k:mi>I</k:mi> </k:mrow> <k:mrow> <k:mi>e</k:mi> </k:mrow> </k:msub> </k:mrow> </k:mfenced> </k:math> index, and atom-bond connectivity temperature ( <p:math xmlns:p="http://www.w3.org/1998/Math/MathML" id="M4"> <p:mi>A</p:mi> <p:mi>B</p:mi> <p:mi>C</p:mi> <p:mi>T</p:mi> </p:math> ) index for the line graph of subdivision graph of tadpole graph <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" id="M5"> <r:mfenced open="(" close=")" separators="|"> <r:mrow> <r:msub> <r:mrow> <r:mi>T</r:mi> </r:mrow> <r:mrow> <r:mi>n</r:mi> <r:mo>,</r:mo> <r:mi>k</r:mi> </r:mrow> </r:msub> </r:mrow> </r:mfenced> </r:math> , ladder graph <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" id="M6"> <w:mfenced open="(" close=")" separators="|"> <w:mrow> <w:msub> <w:mrow> <w:mi>L</w:mi> </w:mrow> <w:mrow> <w:mi>n</w:mi> </w:mrow> </w:msub> </w:mrow> </w:mfenced> </w:math> , and wheel graph <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" id="M7"> <bb:mfenced open="(" close=")" separators="|"> <bb:mrow> <bb:msub> <bb:mrow> <bb:mi>W</bb:mi> </bb:mrow> <bb:mrow> <bb:mi>n</bb:mi> <bb:mo>+</bb:mo> <bb:mn>1</bb:mn> </bb:mrow> </bb:msub> </bb:mrow> </bb:mfenced> </bb:math> . Numerical simulation has also been shown for some novel families of atom-bond connectivity index comparing the three types of indices which can be useful for QSAR and QSPR studies.