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Note on Nordhaus-Gaddum problems for Colin de Verdiere type parameters
(Public Knowledge Network, 2013)
We establish the bounds 4 on the Nordhaus- Gaddum sum upper bound multipliers for all graphs G, in connections with certain Colin de Verdi ere type graph parameters. The Nordhaus-Gaddum sum lower bound is conjectured ...
The maximum nullity of a complete edge subdivision graph is equal to it zero forcing number
(International Linear Algebra Society, 2014-06)
Barrett et al. asked in [W. Barrett et al. Minimum rank of edge subdivisions of graphs. Electronic Journal of Linear Algebra, 18:530–563, 2009.], whether the maximum nullity is equal to the zero forcing number for all ...
Parameters Related to Tree-Width, Zero Forcing, and Maximum Nullity of a Graph
(Wiley Periodicals, Inc., 2013)
Tree-width, and variants that restrict the allowable tree decompositions, play an important role in the study of graph algorithms and have application to computer science. The zero forcing number is used to study the ...
The enhanced principal rank characteristic sequence
The enhanced principal rank characteristic sequence (epr-sequence) of a symmetric n ×n matrix is a sequence from A,S, or N according as all, some, or none of its principal minors of order k are nonzero. Such sequences give ...
The principal rank characteristic sequence over various fields
Given an n-by-n matrix, its principal rank characteristic sequence is a sequence of length n + 1 of 0s and 1s where, for k = 0; 1,..., n, a 1 in the kth position indicates the existence of a principal submatrix of rank ...