On a characterization of complete metrizability of the Hausdorff metric topology
Volume 268 / 2025
                    
                    
                        Fundamenta Mathematicae 268 (2025), 215-223                    
                                        
                        MSC: Primary 54B20; Secondary 54E52, 91A44                    
                                        
                        DOI: 10.4064/fm230623-3-2                    
                                            
                            Published online: 20 February 2025                        
                                    
                                                Abstract
It is shown, under CH, that the Hausdorff metric topology on the hyperspace $CL(X)$ of all nonempty closed subsets of a metric space $(X,d)$ is completely metrizable if and only if $(X,d)$ is completely metrizable and its completion remainder $(\tilde X\setminus X,\tilde d)$ is separable.
 
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            