Let H be a fixed graph without isolated vertices, and let G be a graph on n vertices. Let 2 ≤ k ≤ n− 1 be an integer. We prove that if k ≤ n− 2 and every k-vertex induced subgraph of G is H-decomposable then G or its complement is either a complete graph or a complete bipartite graph. This also holds for k = n − 1 if all the degrees of the vertices of H have a common factor. On the other hand, ...

Let G=(V,E) be a simple connected graph of order p and size q. A decomposition of a graph G is a collection π of edge-disjoint subgraphs G_1,G_2,…,G_n of G such that every edge of G belongs to exactly one G_i,(1≤i ≤n). The decomposition 〖π={G〗_1,G_2,…,G_n} of a connected graph G is said to be a distinct edge geodetic decomposition if g_1 (G_i )≠g_1 (G_j ),(1≤i≠j≤n). The maximum cardinality of π...

ARTICLE INFO An H-magic labeling in a H-decomposable graph G is a bijection f : V (G) ∪ E(G) → {1, 2, ..., p+ q} such that for every copy H in the decomposition, ∑

 ‎Let $V$ be an $n$-dimensional complex inner product space‎. ‎Suppose‎ ‎$H$ is a subgroup of the symmetric group of degree $m$‎, ‎and‎ ‎$chi‎ :‎Hrightarrow mathbb{C} $ is an irreducible character (not‎ ‎necessarily linear)‎. ‎Denote by $V_{chi}(H)$ the symmetry class‎ ‎of tensors associated with $H$ and $chi$‎. ‎Let $K(T)in‎ (V_{chi}(H))$ be the operator induced by $Tin‎ ‎text{End}(V)$‎. ‎Th...

Some bipartite Hamilton decomposable graphs that are regular of degree δ ≡ 2 (mod 4) are shown to have Hamilton decomposable line graphs. One consequence is that every bipartite Hamilton decomposable graph G with connectivity κ(G) = 2 has a Hamilton decomposable line graph L(G).

Let F ={H1, . . . ,Hk} be a family of graphs. A graph G is called totally F -decomposable iffor every linear combination of the form α1e(H1) + · · · + αke(Hk) = e(G) where each αi is anonnegative integer, there is a coloring of the edges of G with α1 + · · · + αk colors such thatexactly αi color classes induce each a copy of Hi, for i = 1, . . . , k. We prove that if F i...

Let F ={H1, . . . ,Hk} be a family of graphs. A graph G with m edges is called totallyF -decomposable if for every linear combination of the form α1e(H1)+ · · ·+αke(Hk) = m whereeach αi is a nonnegative integer, there is a coloring of the edges of G with α1 + · · ·+ αk colorssuch that exactly αi color classes induce each a copy of Hi, for i = 1, . . . , k. We prove that ...

The junction tree representation provides an attractive structural property for organizing a decomposable graph. In this study, we present a novel stochastic algorithm which we call the Christmas tree algorithm for building of junction trees sequentially by adding one node at a time to the underlying decomposable graph. The algorithm has two important theoretical properties. Firstly, every junc...