The Daugavet Equation for Operators on Function Spaces

We prove the norm identity ‖Id+T‖=1+‖T‖, which is known as the Daugavet equation, for weakly compact operatorsTon natural function spaces such as function algebras andL1-predual spaces, provided a non-discreteness assumption is met. We also considerc0-factorable operators and operators onCΛ-spaces.