227 citations · 968 across the 42 of their papers we have counts for
4 papers · 2 filters
Almost Commuting Orthogonal Matrices
Terry A. Loring, Adam P. W. Sørensen
We show that almost commuting real orthogonal matrices are uniformly close to exactly commuting real orthogonal matrices. We prove the same for symplectic unitary matrices. This is…
Principal angles and approximation for quaternionic projections
Terry A. Loring
We extend Jordan's notion of principal angles to work for two subspaces of quaternionic space, and so have a method to analyze two orthogonal projections in M_n(A) for A the real,…
Quantitative K-Theory Related to Spin Chern Numbers
Terry A. Loring
We examine the various indices defined on pairs of almost commuting unitary matrices that can detect pairs that are far from commuting pairs. We do this in two symmetry classes, th…
Estimating Norms of Commutators
Terry A. Loring, Fredy Vides
We find estimates on the norms commutators of the form [f(x), y] in terms of the norm of [x, y] assuming that x and y are contractions in a C*-algebra A, with x normal and with spe…