In this paper we prove that the split graphs of 1,n K and are prime cordial graphs. We also show that the square graph of is a prime cordial graph while middle graph of is a prime cordial graph for . Further we prove that the wheel graph admits prime cordial labeling for . , n n B n  , n n B n P 8 4 n 

LetKn1,n2,...,np denote the complete p-partite graph, p > 1, on n = n1+n2+ · · ·+np vertices and let n1 ≥ n2 ≥ · · · ≥ np > 0. We show that for a fixed value of n, both the spectral radius and the energy of complete p-partite graphs are minimal for complete split graph CS(n, p− 1) and are maximal for Turán graph T (n, p).

We present eecient (parallel) algorithms for two hierarchical clustering heuristics. We point out that these heuristics can also be applied to solve some algorithmic problems in graphs. This includes split decomposition. We show that eecient parallel split decomposition induces an eecient parallel parity graph recognition algorithm. This is a consequence of the result of 7] that parity graphs a...

For any graph G, let V (G) and E(G) denote the vertex set and the edge set of G respectively. The Boolean function graph B(G, L(G),NINC) of G is a graph with vertex set V (G) ∪ E(G) and two vertices in B(G, L(G),NINC) are adjacent if and only if they correspond to two adjacent vertices of G, two adjacent edges of G or to a vertex and an edge not incident to it in G. For brevity, this graph is d...

A problem is said to be GI-complete if it is provably as hard as graph isomorphism; that is, there is a polynomial-time Turing reduction from the graph isomorphism problem. It is known that the GI problem is GI-complete for some special graph classes including regular graphs, bipartite graphs, chordal graphs and split graphs. In this paper, we prove that deciding isomorphism of double split gra...

In this paper, we define the notions of inverse strong non-split r-dominating set and inverse strong non-split r-domination number γ′snsr(G) of a graph G. We characterize graphs for which γsnsr(G) + γ′snsr(G) = n, where γsnsr(G) is the strong non-split r-domination number of G. We get many bounds on γ′snsr(G). Nordhaus-Gaddum type results are also obtained for this new parameter.

In the geodetic convexity, a set of vertices S graph G is convex if all belonging to any shortest path between two lie in . The hull H ( ) smallest containing If = V ), then cardinality h minimum number complementary prism GḠ arises from disjoint union and Ḡ by adding edges perfect matching corresponding A autoconnected both are connected. Motivated previous work, we study for prisms graphs. Wh...

We consider a Q-polynomial distance-regular graph Γ with vertex set X and diameter D ≥ 3. For μ, ν ∈ {↓, ↑} we define a direct sum decomposition of the standard module V = CX, called the (μ, ν)–split decomposition. For this decomposition we compute the complex conjugate and transpose of the associated primitive idempotents. Now fix b, β ∈ C such that b 6= 1 and assume Γ has classical parameters...