Products of EP operators on Hilbert C*-modules

In this paper, the special attention is given to the product of two modular operators, and when at least one of them is EP,some interesting results is made, so the equivalent conditions are presented that imply the product of operators is EP. Also, some conditions are provided, for which the reverse order law is hold.Furthermore, it is proved that P(RPQ)yis idempotent, if RPQhas closed range, for orthogonal projections P;Q and R.

Keywords:

Closed range , EP operators , Moore-Penrose inverse , Hilbert C-module