Generalized Schur complements and P-complementable operators

Anderson, 1975, Shorted operators II, SIAM J. Appl. Math, 28, 60, 10.1137/0128007 J.A. Antezana, Shorted de Operadores, grade thesis UNLP, 2002 Choi, 1975, Completely positive maps on complex matrices, Linear Algebra Appl, 10, 285, 10.1016/0024-3795(75)90075-0 Corach, 2001, Schur complements and oblique projections, Acta Sci. Math. (Szeged), 67, 439 Corach, 2002, Generalized Schur complements and oblique projections, Linear Algebra Appl, 341, 259, 10.1016/S0024-3795(01)00384-6 Corach, 2002, Oblique projections and abstract splines, J. Approx. Theory, 117, 189, 10.1006/jath.2002.3696 Corach, 2001, Index of Hadamard multiplication by positive matrix II, Linear Algebra Appl, 332–334, 504 Douglas, 1966, On majorization, factorization and range inclusion of operators in Hilbert space, Proc. Amer. Math. Soc, 17, 413, 10.1090/S0002-9939-1966-0203464-1 Fiedler, 1995, An observation on the Hadamard product of Hermitian matrices, Linear Algebra Appl, 215, 179, 10.1016/0024-3795(93)00087-G Fillmore, 1971, On operator ranges, Adv. Math, 7, 254, 10.1016/S0001-8708(71)80006-3 Li, 2000, Extrernal characterizations of the Schur complement and resulting inequalities, SIAM Rev, 42, 233, 10.1137/S0036144599337290 Longo, 1989, Index of subfactors and statistics of quantum fields, I, Comm. Math. Phys, 126, 217, 10.1007/BF02125124 Paulsen, 1989, Schur products and matrix completions, J. Funct. Anal, 85, 151, 10.1016/0022-1236(89)90050-5 Pekarev, 1992, Shorts of operators and some extremal problems, Acta Sci. Math. (Szeged), 56, 147 Reams, 1999, Hadamard inverses, squares roots and products of almost semidefinite matrices, Linear Algebra Appl, 288, 35, 10.1016/S0024-3795(98)10162-3 Stojanoff, 1999, Index of Hadamard multiplication by positive matrices, Linear Algebra Appl, 290, 95, 10.1016/S0024-3795(98)10215-X Schur, 1911, Bemerkungen zur Theorie der beschränkten Bilinearformen mit unendlich vielen Veränderlichen, J. Reine Angew. Math, 140, 1, 10.1515/crll.1911.140.1