Bulletin of the International Mathematical Virtual Institute

13-19

Authors: Ivan Gutman

Let G be a graph with vertex set V (G) and edge set E(G) . The ¯rst and second multiplicative Zagreb indices of G are ¦1 = Q x2V (G) deg(x)2 and ¦2 = Q xy2E(G) deg(x) deg(y) , respectively, where deg(v) is the de- gree of the vertex v . Let Tn be the set of trees with n vertices. We determine the elements of Tn , extremal w.r.t. ¦1 and ¦2 .

27-38

Authors: R. A. Rashwan and S. I. Maustafa

In this paper, we show that some results of Sharma and Deshpande [19] are not valid, we also give supporting example. Finally, we consider the concept of weakly compatible mappings to improve the main result of Pathak [9].

45-51

Authors: R. A. Rashwan

In this paper, we discuss the convergence of random Ishikawa iteration scheme to a common random ¯xed point for a certain class of random op- erators in Banach spaces.

59-65

Authors: N. Rajesh and V.Vijayabharathy

Generalized open sets play a very important role in General Topology and they are now the research topic of many topologists worldwide. Indeed a signi¯cant theme in General Topology and Real Analysis concerns the various modi¯ed forms of continuity, seperation axioms etc. by utilizing generalized open sets. Kasahara [5] de¯ned the concept of an operation on topological spaces. Umehara et. al. [7] introduced the notion of ¿(°;°0) which is the collection of all (°; °0)-open sets in a topological space (X; ¿ ). Recently, G. S. S. Krishnan and K. Balachandran (see [1], [3], [2]) studied in this ¯eld. In this paper, we introduce and study the concepts of minimal (°; °0)-open and maximal (°; °0)-closed sets in topological spaces. In this paper, we de¯ne (°; °0)-connected spaces and study their properties in topological spaces.