We develop protocols for preparing the GHZ state (a pure tri-partite maximally entangled state) and, in general, a pure n-partite maximally entangled state using EPR pairs shared amongst n agents and classical communication between the agents. We observe that the combinatorial arrangement of EPR pairs required for this purpose is like that in Helly-type theorems in geometry. PACS numbers: 03.65...

Turán’s Theorem states that every graphG of edge density ‖G‖/ (|G| 2 ) > k−2 k−1 contains a complete graph K and describes the unique extremal graphs. We give a similar Theorem for `-partite graphs. For large `, we find the minimal edge density d` , such that every `-partite graph whose parts have pairwise edge density greater than d` contains a K . It turns out that d` = k−2 k−1 for large enou...

Let G be a bipartite graph, and let λe, λi be two parallel convex curves; we study the question about whether G admits a planar straight line drawing such that the vertices of one partite set of G lie on λe and the vertices of the other partite set lie on λi. A characterization is presented that gives rise to linear time testing and drawing algorithms.

‎Unmixed bipartite graphs have been characterized by Ravindra and‎ ‎Villarreal independently‎. ‎Our aim in this paper is to‎ ‎characterize unmixed $r$-partite graphs under a certain condition‎, ‎which is a generalization of Villarreal's theorem on bipartite‎ ‎graphs‎. ‎Also, we give some examples and counterexamples in relevance to this subject‎.

Quantum circuits are provided for realizing quantum communicational protocols involving teleportation and quantum information splitting (QIS) of single and two qubit states. We explicate these protocols through cluster states as the same is experimentally achievable. We describe quantum circuits for realizing the four and five partite cluster states using well known gates in quantum information...

A graph G is called a complete k-partite (k ≥ 2) graph if its vertices can be partitioned into k independent sets V1, . . . , Vk such that each vertex in Vi is adjacent to all the other vertices in Vj for 1 ≤ i < j ≤ k. A complete k-partite graph G is a complete balanced kpartite graph if |V1| = |V2| = · · · = |Vk|. An edge-coloring of a graph G with colors 1, . . . , t is an interval t-colorin...