Least Squares Approximate and Least Norm Solutions of Paired Singular Equations
Frank‐Olme Speck · Mathematische Nachrichten · 1987
Paired operators T = A1P + A2Q on a HILBERT space are studied where P is a projector, P + Q = I, and the coefficients are linear invertible operators. The MOORE-PENROSE inverse of T can be obtained explicitly from a factorization of the coefficients, which is equivalent to the normal solvability of T and occurs in numerous applications. As an example, systems of singular integral equations of CAUCHY type are analysized in detail.