Some Notes On Spectra Of Cographs

Polar cographs

Polar graphs are a natural extension of some classes of graphs like bipartite graphs, split graphs and complements of bipartite graphs. A graph is (s, k)-polar if there exists a partition A, B of its vertex set such that A induces a complete s-partite graph (i.e., a collection of at most s disjoint stable sets with complete links between all sets) and B a disjoint union of at most k cliques (i....

Counting Spanning Trees in Cographs

Some notes on the existence of an inequality in Banach algebra

We shall prove an existence inequality for two maps on Banach algebra, withan example and in sequel we have some results on R and Rn spaces. This waycan be applied for generalization of some subjects of mathematics in teachingwhich how we can extend a math problem to higher level.

Some notes for topological centers on the duals of Banach algebras

We introduce  the weak topological centers of left and right module actions and we study some of their properties.  We investigate the relationship between these new concepts and the  topological centers of of left and right module actions with some results in the group algebras.

On the Grundy number of Cameron graphs

TheGrundynumber of a graph is themaximal number of colors attained by a first-fit coloring of the graph. The class of Cameron graphs is the Seidel switching class of cographs. In this paper we show that the Grundy number is computable in polynomial time for Cameron graphs.