On local automorphisms and mappings that preserve idempotents
Volume 113 / 1995
                    
                    
                        Studia Mathematica 113 (1995), 101-108                    
                                        
                        DOI: 10.4064/sm-113-2-101-108                    
                                    
                                                Abstract
Let B(H) be the algebra of all bounded linear operators on a Hilbert space H. Automorphisms and antiautomorphisms are the only bijective linear mappings θ of B(H) with the property that θ(P) is an idempotent whenever P ∈ B(H) is. In case H is separable and infinite-dimensional, every local automorphism of B(H) is an automorphism.
 
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            