Abstract:
                                      Let 
H
 be an infinite dimensional complex separable Hilbert space and 
B(H)
 be the algebra of all bounded linear operators on 
H
. 
T \in B(H)
 is said to satisfy property 
(R_1)
 if 
\sigma _a(T)\backslash \sigma _ab(T) \subseteq \pi _00(T)
, where 
\sigma _a(T)
 and 
\sigma _ab(T)
 denote the approximate point spectrum and the Browder essential approximate point spectrum of 
T
 respectively, and 
\pi _00(T) = \ \lambda  \in \rmiso\sigma (T):0  <  \rmdimN(T - \lambda I)  <  \infty \ 
. If 
\sigma _a(T)\backslash \sigma _ab(T) = \pi _00(T)
, 
T
 is said to satisfy property 
(R)
. In this paper, by using the new spectrum, the necessary and sufficient conditions for which the property 
(R_1)
 or property 
(R)
 holds for bounded linear operators and its functions are given. Also, the new judgements for a-Weyl's theorem and property 
(R)
 are obtained.