Abstract
Baksalary and Baksalary [Linear Algebra Appl. 321 (2000) 3] established a complete solution to the problem of when a linear combination of two different projectors is also a projector by listing all situations in which nonzero complex numbers c 1, c 2 and nonzero complex matrices P 1 , P 2 ( P 1≠ P 2 ) satisfying P i 2= P i , i=1,2, form a matrix P =c 1 P 1+c 2 P 2 such that P 2= P . In the present paper, the same problem is considered for generalized projectors G 1 and G 2 defined by Groß and Trenkler [Linear Algebra Appl. 264 (1997) 463] as matrices satisfying G i 2= G i ∗ , i=1,2. Their results concerning the sum G 1+ G 2 and difference G 1− G 2 appear to be very special cases of the general solution established herein.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
