The Sigma Coindex of Graph Operations
Keyword(s):
The sigma coindex is defined as the sum of the squares of the differences between the degrees of all nonadjacent vertex pairs. In this paper, we propose some mathematical properties of the sigma coindex. Later, we present precise results for the sigma coindices of various graph operations such as tensor product, Cartesian product, lexicographic product, disjunction, strong product, union, join, and corona product.
2019 ◽
Vol 11
(05)
◽
pp. 1950054
◽
Keyword(s):
Keyword(s):
2019 ◽
Vol 8
(3)
◽
pp. 8536-8545
2015 ◽
Vol 9
(1)
◽
pp. 39-58
◽
2016 ◽
Vol 17
◽
pp. 10-16
Keyword(s):