Spectral Recognition of Graphs
Spectral saturation: inverting the spectral Turán theorem.
Spectral study of alliances in graphs
In this paper we obtain several tight bounds on different types of alliance numbers of a graph, namely (global) defensive alliance number, global offensive alliance number and global dual alliance number. In particular, we investigate the relationship between the alliance numbers of a graph and its algebraic connectivity, its spectral radius, and its Laplacian spectral radius.
Spectral Techniques in Complex Networks
Spectrally arbitrary complex sign pattern matrices.
Spectrally arbitrary tree sign patterns of order 4.
Spectrum Of The Total Graph Of A Graph
Spectrum of two new joins of graphs and infinite families of integral graphs
Spherical and clockwise spherical graphs
The main subject of our study are spherical (weakly spherical) graphs, i.e. connected graphs fulfilling the condition that in each interval to each vertex there is exactly one (at least one, respectively) antipodal vertex. Our analysis concerns properties of these graphs especially in connection with convexity and also with hypercube graphs. We deal e.g. with the problem under what conditions all intervals of a spherical graph induce hypercubes and find a new characterization of hypercubes: is...
Spherical F-tilings by triangles and -sided regular polygons, .
Spherical Functions and a q-Analogue of Kostant's Weight Multiplicity Formula.
Spin-preserving Knuth correspondences for ribbon tableaux.
Splitting Cubic Circle Graphs
We show that every 3-regular circle graph has at least two pairs of twin vertices; consequently no such graph is prime with respect to the split decomposition. We also deduce that up to isomorphism, K4 and K3,3 are the only 3-connected, 3-regular circle graphs.
Squarefree monomial ideals with maximal depth
Let be a Noetherian local ring and a finitely generated -module. We say has maximal depth if there is an associated prime of such that depth . In this paper we study squarefree monomial ideals which have maximal depth. Edge ideals of cycle graphs, transversal polymatroidal ideals and high powers of connected bipartite graphs with this property are classified.
Square-ice enumeration.
Square-root rule of two-dimensional bandwidth problem
The bandwidth minimization problem is of significance in network communication and related areas. Let G be a graph of n vertices. The two-dimensional bandwidth B2(G) of G is the minimum value of the maximum distance between adjacent vertices when G is embedded into an n × n grid in the plane. As a discrete optimization problem, determining B2(G) is NP-hard in general. However, exact results for this parameter can be derived for some special classes of graphs. This paper studies the “square-root...
Square-root rule of two-dimensional bandwidth problem∗
The bandwidth minimization problem is of significance in network communication and related areas. Let G be a graph of n vertices. The two-dimensional bandwidth B2(G) of G is the minimum value of the maximum distance between adjacent vertices when G is embedded into an n × n grid in the plane. As a discrete optimization problem, determining B2(G) is NP-hard in general. However, exact results for this parameter can be derived for some special classes of graphs. This paper studies the “square-root...
Squares in difference sets
Squares of triangular cacti
Square-stable and well-covered graphs.