Explicit bounds for the pseudospectra of various classes of matrices and operators
Feixue Gong, Olivia S. Meyerson, Jeremy Meza, Mihai Stoiciu, Abigail Ward · Involve a Journal of Mathematics · 2016
We study the ε-pseudospectra σ ε (A) of square matrices A ∈ ރ N ×N .We give a complete characterization of the ε-pseudospectra of 2×2 matrices and describe the asymptotic behavior (as ε → 0) of σ ε (A) for every square matrix A. We also present explicit upper and lower bounds for the ε-pseudospectra of bidiagonal matrices, as well as for finite-rank operators.