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math.CO2019
Null Decomposition of Unicyclic Graphs
Luiz Emilio Allem, Daniel Alejandro Jaume, Gonzalo Molina +2
In this work we obtain basis for the null space of unicyclic graphs. We extend the null decomposition of trees from [11] for unicyclic graphs. As an application, we obtain closed f…
math.CO2019
Independence and Matching Numbers of Unicyclic Graphs From Null Space
Luiz Emilio Allem, Daniel Alejandro Jaume, Gonzalo Molina +2
We characterize unicyclic graphs that are singular using the support of the null space of their pendant trees. From this, we obtain closed formulas for the independence and matchin…
math.CO2019
Integral cographs and applications
Luiz Emilio Allem, Fernando Tura
A graph is called integral if all the eigenvalues of its adjacency matrix are integers. In this paper, we show a cograph that has a balanced cotree $T_{G}(a_{1},\ldots,a_{r-1},0|0,…