Approximation theorems for positive operators on Lp-spaces

AbstractLet 1 < r ⩽ p < ∞. Approximation theorems for positive contractions in L(Lp(m), Lr(n)) are presented. The characterization of norm attaining extreme positive contractions is given. Note that these extreme operators are also exposed points of the positive part of the unit ball of L(lp, lr)