Automorphisms of Hilbert space effect algebras Original Research Article

We consider bijections of the Hilbert space effect algebra that preserve the algebraic structures in one direction and have some other properties. It is shown that if image is conditionally multiplicative and conditionally additive, then phi is implemented by a unitary or antiunitary operator on image. We also show that 2-local ortho-order automorphisms on image are of the same form if image.