Strong ball proximinality of the space of compact operators
Tom 268 / 2023
                    
                    
                        Studia Mathematica 268 (2023), 51-64                    
                                        
                        MSC: Primary 46B20; Secondary 41A65, 46B28, 47B07.                    
                                        
                        DOI: 10.4064/sm211009-29-5                    
                                            
                            Opublikowany online: 20 July 2022                        
                                    
                                                Streszczenie
We prove that the closed unit ball of the space of compact operators on a Hilbert space is strongly proximinal in the corresponding space of all bounded operators under an additional assumption. We also give a sufficient condition for an $M$-summand to be strongly ball proximinal. In addition, we prove that the space of bounded operators on a Hilbert space is strongly ball proximinal in itself under an additional assumption.
 
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            