On permutation polynomials over finite fields.
For given a graph , a graphic sequence is said to be potentially -graphic if there is a realization of containing as a subgraph. In this paper, we characterize the potentially -positive graphic sequences and give two simple necessary and sufficient conditions for a positive graphic sequence to be potentially -graphic, where is a complete graph on vertices and is a graph obtained from by deleting one edge. Moreover, we also give a simple necessary and sufficient condition for...
Let be the graph obtained from by removing the edges set of where is a subgraph of . In this paper, we characterize the potentially and -graphic sequences where is a tree on 5 vertices and 3 leaves.
A matrix whose entries come from the set is called a sign pattern matrix, or sign pattern. A sign pattern is said to be potentially nilpotent if it has a nilpotent realization. In this paper, the characterization problem for some potentially nilpotent double star sign patterns is discussed. A class of double star sign patterns, denoted by , is introduced. We determine all potentially nilpotent sign patterns in and , and prove that one sign pattern in is potentially stable.
A graph of order is said to be a prime graph if its vertices can be labeled with the first positive integers in such a way that the labels of any two adjacent vertices in are relatively prime. If such a labeling on exists then it is called a prime labeling. In this paper we seek prime labeling for union of tadpole graphs. We derive a necessary condition for the existence of prime labelings of graphs that are union of tadpole graphs and further show that the condition is also sufficient...