Spaces with maximal projection constants
Volume 159 / 2003
                    
                    
                        Studia Mathematica 159 (2003), 357-372                    
                                        
                        MSC: Primary 46B20.                    
                                        
                        DOI: 10.4064/sm159-3-2                    
                                    
                                                Abstract
We show that $n$-dimensional spaces with maximal projection constants exist not only as subspaces of $l_\infty $ but also as subspaces of $l_1$. They are characterized by a rigid set of vector conditions. Nevertheless, we show that, in general, there are many non-isometric spaces with maximal projection constants. Several examples are discussed in detail.