有限维代数扩张的同构与维数群

Isomorphisms and Dimension Groups of Extensions of Finite Dimensional Algebras

对于有限维C＊-代数A，证明了其本质扩张的同构与酉等价是一致的，由此证明了扩张群Ext（A）中的等价类是区分该类扩张代数的完全不变量，并利用Bratteli图计算出它们的维数群．

In this paper we prove that isomorphism equivalence and unitary equivalence of essential extensions of finite dimensional C＊-algebras by κ are equivalent. We also give the dimension groups of these extension algebras and prove that they ave stably isomorphic but not isomorphic.