Many economic and social situations can be represented by a digraph. Both axiomatic and iterativemethods to determine the strength or power of all the nodes in a digraph have been proposed inthe literature. We propose a new method, where the power of a node is determined by both thenumber of its...

We argue that Islamic principles, in particular the avoidance of ribā and gharar should be applied with respect to real economic value rather than to monetary value in terms of conventional currency. In order to reconcile monetary value with economic value, we propose a reference currency...

We consider k-regular graphs with loops, and study the Lovasz O-numbers and Schrijver O-numbers of the graphs that result when the loop edges are removed. We show that the O-number dominates a recent eigenvalue upper bound on the stability number due to Godsil and Newman [C.D. Godsil and M.W....

This paper aims to provide a mathematical justification for asset allocation. Asset allocation is widely employed in practice, yet the question of its efficiency remains open. Asset allocation allows portfolio managers to concentrate on a relatively small number of assets, while security...