Abstract. Let X and Y be Banach spaces, and L(X, Y ) be the spaces of bounded linear operators from X into Y. In this paper we give full characterization of isometric onto operators of L(X, Y ), for a certain class of Banach spaces, that includes p , 1 < p < ∞. We also characterize the isometric onto operators of L(c 0 ) and K( 1 ), the compact operators on 1 . Furthermore, the multiplicative isometric onto operators of L( 1 ), when multiplication on L( 1 ) is taken to be the Schur product, are characterized.
IntroductionLet X and Y be Banach spaces, and L(X, Y ) the space of bounded linear oper- [12], it was proved that every isometry of a semisimple commutative Banach algebra that preserves the identity is multiplicative. In this paper, we give a full characterization of isometric onto operators of L(X, Y ), for a class of Banach spaces that includes p , 1 < p < ∞. Isometric onto operators of L(c 0 ), and K( 1 ), the compact operators on 1 , are also fully characterized in this paper. Furthermore, multiplicative isometric onto operators of L( 1 ) when multiplication on L( 1 ) is taken to be the Schur product are characterized.Throughout this paper, if X is a Banach space, X * is the dual ofwhere the sum is a direct summand, in the sense, if