Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Maximal doubly stochastic matrix centralizersPublication . Cruz, Henrique F. da; Dolinar, Gregor; Fernandes, Rosário; Kuzma, BojanWe describe doubly stochastic matrices with maximal central-izers.
- The number of P-vertices in a matrix with maximum nullityPublication . Fernandes, Rosário; Cruz, Henrique F. DaLet T be a tree with n≥2 vertices. Set S(T) for the set of all real symmetric matrices whose graph is T. Let A∈S(T) and i∈{1,…,n} . We denote by A(i) the principal submatrix of A obtained after deleting the row and column i. We set mA(i)(0)=mA(0)+1, we say that i is a P-vertex of A. As usual, M(T) denotes the maximum nullity occurring of B∈S(T). In this paper we determine an upper bound and a lower bound for the number of P-vertices in a matrix A∈S(T)with nullity M(T). We also prove that if the integer b is between these two bounds, then there is a matrix E∈S(T) with b P-vertices and maximum nullity.