Riduzioni boreliane e il problema di isomorfismo per C*-algebre separabili

Classification problems are typical of almost every area of mathematics. Descriptive set theory offers the solid framework of Borel reducibility, in which the study of such type of problems can be formalized and organized. In this thesis we first present the Borel reducibility and some important general results in this area. After that, we analyse a concrete example in which the framework has been used to solve (with negative answer) the classification problem for separable C*-algebras up to isomorphism.