4 papers
Optimization problem for star covers of graphs without four cycles
Damjana Kokol Bukovšek, Polona Oblak, Helena Šmigoc
This work presents a study of star covers on graphs. Unlike traditional formulations that minimize the number of stars, our aim is to optimize the number of bipartite components us…
Combinatorial aspects of the non-symmetric strong spectral property for graphs
Sara KoljanÄiÄ, Polona Oblak
In this paper, we investigate the non-symmetric Strong Spectral Property (nSSP) from a combinatorial perspective. To zero-nonzero patterns of matrices we associate directed graphs…
Orthogonalisability of joins of graphs
Rupert H. Levene, Polona Oblak, Helena Å migoc
A graph is said to be orthogonalisable if the set of real symmetric matrices whose off-diagonal pattern is prescribed by its edges contains an orthogonal matrix. We determine some…
The strong spectral property for some families of unicyclic graphs
Sara KoljanÄiÄ, Polona Oblak
To find all the possible spectra of all real symmetric matrices whose off-diagonal pattern is prescribed by the adjacencies of a given graph , the Strong Spectral Property turne…