Orthogonality of bounded linear operators on complex Banach spaces

Document Type: Original Article


1 Department of Mathematics Jadavpur University Kolkata 700032 India

2 Indian Institute of Science, Bengaluru


‎We study Birkhoff-James orthogonality of compact linear operators on complex reflexive Banach spaces and obtain its characterization‎. ‎By means of introducing new definitions‎, ‎we illustrate that it is possible in the complex case‎, ‎to develop a study of orthogonality of compact linear operators‎, ‎analogous to the real case‎. ‎Furthermore‎, ‎earlier operator theoretic characterizations of Birkhoff-James orthogonality in the real case‎, ‎can be obtained as simple corollaries to our present study‎. ‎In fact‎, ‎we obtain more than one equivalent characterizations of Birkhoff-James orthogonality of compact linear operators in the complex case‎, ‎in order to distinguish the complex case from the real case‎.