3 papers
math.CO2024
Edge-apexing in hereditary classes of graphs
Jagdeep Singh, Vaidy Sivaraman
A class of graphs is called hereditary if it is closed under taking induced subgraphs. We denote by the class of graphs that are at most one edge away from…
math.CO2023
Hereditary Nordhaus-Gaddum Graphs
Vaidy Sivaraman, Rebecca Whitman
Nordhaus and Gaddum proved in 1956 that the sum of the chromatic number of a graph and its complement is at most . The Nordhaus-Gaddum graphs are the class of graphs…
math.CO2014
Frustration in signed graphs
Vaidy Sivaraman
Zaslavsky conjectured the following: The minimum number of vertices to be deleted to restore balance in a subcubic signed graph is the same as the minimum number of edges to be del…