Monotone matrix functions of two variables

T. Ando, Topics on operator inequalities, Lecture Notes, Hokkaido University, Sapporo, 1978 Aujla, 1993, Matrix convexity of functions of two variables, Linear Algebra Appl., 194, 149, 10.1016/0024-3795(93)90119-9 Bhatia, 1997 A.L. Brown, H.L. Vasudeva, The calculus of operator functions and operator convexity, Dissertation Mathemaicae, Polish Acad Sci., Warsaw, to appear Donoghue, 1974 Flett, 1980 F. Hansen, Operator convex functions of several variables, Publ. RIMS, Kyoto Univ. 33 (1997) 443–463 Hansen, 1982, Jensen's inequality for operators and Löwner's theorem, Math. Ann., 258, 229, 10.1007/BF01450679 Korányi, 1961, On some classes of analytic functions of several variables, Trans. Amer. Math. Soc., 101, 520, 10.2307/1993476 Löwner, 1934, Über monotone Matrixfunctionen, Math. Z., 38, 177, 10.1007/BF01170633 W. Rudin, Functional Analysis, Tata McGraw-Hill, New York Treves, 1967 Vasudeva, 1973, On monotone matrix functions of two variables, Trans. Amer. Math. Soc., 176, 305, 10.1090/S0002-9947-1973-0313855-4