the concept of geometric-arithmetic indices (ga) was put forward in chemical graph theoryvery recently. in spite of this, several works have already appeared dealing with these indices.in this paper we present lower and upper bounds on the second geometric-arithmetic index(ga2) and characterize the extremal graphs. moreover, we establish nordhaus-gaddum-typeresults for ga2.

continuing the work k. c. das, i. gutman, b. furtula, on second geometric-arithmetic indexof graphs, iran. j. math chem., 1(2) (2010) 17-28, in this paper we present lower and upperbounds on the third geometric-arithmetic index ga3 and characterize the extremal graphs.moreover, we give nordhaus-gaddum-type result for ga3.

No abstract is available for this article.

Please Click to download the index of this issue.

Please Click to download the index of this issue.

land degradation, or desertification, is specific to arid, semi-arid, and dry sub-humid regions. the rate of thisphenomenon is high in developing countries such as iran. this research investigated desertification and mapping ofdesertification in abuzaydabad, near kashan, iran, with an emphasis on land criteria using an imdpa model.different studies have assessed land degradation or desertificat...

a lot of research and various techniques have been devoted for finding the topologicaldescriptor wiener index, but most of them deal with only particular cases. there exist threeregular plane tessellations, composed of the same kind of regular polygons namely triangular,square, and hexagonal. using edge congestion-sum problem, we devise a method to computethe wiener index and demonstrate this m...