5 papers
Qualitative, statistical and extreme properties of spectral indices of signable pseudo-invertible graphs
Sona Pavlikova, Daniel Sevcovic
In this paper, we investigate the Moore-Penrose inversion of a simple connected graph. We analyze qualitative, statistical, and extreme properties of spectral indices of signable p…
Orientably-regular embeddings of complete multigraphs
Stefan Gyurki, Sona Pavlikova, Jozef Siran
An embedding of a graph on an orientable surface is orientably-regular (or rotary, in an equivalent terminology) if the group of orientation-preserving automorphisms of the embeddi…
Extreme and statistical properties of eigenvalue indices of simple connected graphs
Sona Pavlikova, Daniel Sevcovic, Jozef Siran
We analyze graphs attaining the extreme values of various spectral indices in the class of all simple connected graphs, as well as in the class of graphs which are not complete mul…
Invertibility of graphs with a unique perfect matching
Sona Pavlikova, Daniel Sevcovic
In this paper we investigate invertibility of graphs with a unique perfect matching, i.e. graphs having a unique 1-factor. We recall the new notion of the so-called negatively inve…
Maximization of the Spectral Gap for Chemical Graphs by means of a Solution to a Mixed Integer Semidefinite Program
Sona Pavlikova, Daniel Sevcovic
In this paper we analyze the spectral gap of a weighted graph which is the difference between the smallest positive and largest negative eigenvalue of its adjacency matrix. Such a…