Finite rank elements in semisimple Banach algebras
Volume 128 / 1998
                    
                    
                        Studia Mathematica 128 (1998), 287-298                    
                                        
                        DOI: 10.4064/sm-128-3-287-298                    
                                    
                                                Abstract
Let A be a semisimple Banach algebra. We define the rank of a nonzero element a in the socle of A to be the minimum of the number of minimal left ideals whose sum contains a. Several characterizations of rank are proved.
 
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            