On column and null spaces of functions of a pair of oblique projectors
Oskar Maria Baksalary, Götz Trenkler · Linear and Multilinear Algebra · 2012
A number of characterizations involving column and null spaces of various functions of a pair of oblique projectors are established. Particular attention is paid to properties of a product of the two projectors, but other functions of the pair (such as sum, difference or sum and difference of products) are considered as well. In many cases, the results obtained generalize those already known to be valid for orthogonal projectors.