Positivity of Block Tridiagonal Matrices
Martin Böhner, Ondřej Došlý · SIAM Journal on Matrix Analysis and Applications · 1998
This paper relates disconjugacy of linear Hamiltonian difference systems (LHdS) (and hence positive definiteness of certain discrete quadratic functionals) to positive definiteness of some block tridiagonal matrices associated with these systems and functionals. As a special case of a Hamiltonian system, Sturm--Liouville difference equations are considered, and analogous results are obtained for these important objects.