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6 papers · 1 filter

math.CO2026

Computation of small reflective and dihedral Ramsey numbers

Ivan Damnjanović, Irena Đorđević

Throughout, all graphs are simple, finite and have vertex sets of the form for some . For graphs and , and a permutation gro…

math.CO2025

On the degrees of regular nut graphs and Cayley nut graphs

Nino Bašić, Ivan Damnjanović, Patrick W. Fowler

A nut graph is a simple graph for which the adjacency matrix has a single zero eigenvalue such that all non-zero kernel eigenvectors have no zero entry. It is known that infinitely…

math.CO2025

Nut graphs with a prescribed number of vertex and edge orbits

Nino Bašić, Ivan Damnjanović

A nut graph is a nontrivial graph whose adjacency matrix has a one-dimensional null space spanned by a vector without zero entries. Recently, it was shown that a nut graph has more…

math.CO2025

Classification of quartic bicirculant nut graphs

Ivan Damnjanović, Nino Bašić, Tomaž Pisanski +1

A graph is called a nut graph if zero is its eigenvalue of multiplicity one and its corresponding eigenvector has no zero entries. A graph is a bicirculant if it admits an automorp…

math.CO2024

Some bounds on the spectral radius of connected threshold graphs

Péter Csikvári, Ivan Damnjanović, Dragan Stevanović +1

The spectral radius of a graph is the spectral radius of its adjacency matrix. A threshold graph is a simple graph whose vertices can be ordered as , so that…

math.CO2024

On cubic polycirculant nut graphs

Nino Bašić, Ivan Damnjanović

A nut graph is a nontrivial simple graph whose adjacency matrix contains a one-dimensional null space spanned by a vector without zero entries. Moreover, an -circulant graph…