Add to ORKGA simple graph is reflexive if its second largest eigenvalue λ2 is less than or equal to 2. A graph is a cactus, or a treelike graph, if any pair of its cycles (circuits) has at most one common vertex. For a lot of cactuses the property λ2 ≤ 2 can be tested by identifying and deleting a single cut-vetex (Theorem 1). if this theorem cannot be applied to a connected reflexive cactus and if all its cycles do not form a bundle, such a graph has at most five cycles. On the same conditions, in this paper we find some classes of maximal reflexive cactuses with four cycles. The complete case of four cycles, together with that of five cycles, is being settled in [10]. 1
Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has ...
Among all connected cactuses with n vertices we find a unique graph whose largest eigenvalue (index,...
A cactus is a connected graph in which each edge belongs to at most one cycle. A graph H is a cactus...
A simple graph is reflexive if the second largest eigenvalue of its (0, 1) adja-cency matrix does no...
AbstractA simple graph is reflexive if its second largest eigenvalue does not exceed 2. A graph is t...
AbstractCacti, or treelike graphs, are graphs whose all cycles are mutually edge-disjoint. Graphs wi...
AbstractThe spectrum of a graph is the family of eigenvalues of its (0,1) adjacency matrix. A simple...
AbstractA simple graph is said to be reflexive if the second largest eigenvalue of a (0,1)-adjacency...
A cactus is a connected graph whose all the blocks are isomorphic to cycle or complete graph on n ve...
In this paper a new class of vertex decomposable graphs are determined. Moreover, all shellable and ...
In this paper a new class of vertex decomposable graphs are determined. Moreover, all shellable and ...
CombinatoricsConnected graphs in which any two of its cycles have at most one common vertex are call...
A cactus graph is a graph in which any two cycles are edge-disjoint. We present a constructive proof...
AbstractA connected graph G is a cactus if any two of its cycles have at most one common vertex. In ...
Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has ...
Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has ...
Among all connected cactuses with n vertices we find a unique graph whose largest eigenvalue (index,...
A cactus is a connected graph in which each edge belongs to at most one cycle. A graph H is a cactus...
A simple graph is reflexive if the second largest eigenvalue of its (0, 1) adja-cency matrix does no...
AbstractA simple graph is reflexive if its second largest eigenvalue does not exceed 2. A graph is t...
AbstractCacti, or treelike graphs, are graphs whose all cycles are mutually edge-disjoint. Graphs wi...
AbstractThe spectrum of a graph is the family of eigenvalues of its (0,1) adjacency matrix. A simple...
AbstractA simple graph is said to be reflexive if the second largest eigenvalue of a (0,1)-adjacency...
A cactus is a connected graph whose all the blocks are isomorphic to cycle or complete graph on n ve...
In this paper a new class of vertex decomposable graphs are determined. Moreover, all shellable and ...
In this paper a new class of vertex decomposable graphs are determined. Moreover, all shellable and ...
CombinatoricsConnected graphs in which any two of its cycles have at most one common vertex are call...
A cactus graph is a graph in which any two cycles are edge-disjoint. We present a constructive proof...
AbstractA connected graph G is a cactus if any two of its cycles have at most one common vertex. In ...
Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has ...
Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has ...
Among all connected cactuses with n vertices we find a unique graph whose largest eigenvalue (index,...
A cactus is a connected graph in which each edge belongs to at most one cycle. A graph H is a cactus...