幂等元积与差的群可逆性

摘要

设U为具有单位元I的Banach代数,P,Q为其上的幂等元.给出P-Q,PQ,PQ-QP为群逆的等价刻画.%Let P and Q be idempotents on the Banach algebra U with unit I.In this paper,the group invertibility of P-Q,PQ,PQ-QP was studied.