|    | 
      
	   |  
          
            John Froelich and Ben Mathes 
            Bi-Strictly Cyclic Operators 
             |  
			 
			 |  
			
              
                | Published: | 
                April 10, 1995  | 
               
              
                | Keywords: | 
                Strictly cyclic, invariant subspace, column Hilbert space, completely bounded, completely isomorphic. | 
               
              
                | Subject: | 
                Primary 47A15; Secondary 46B28. | 
               
              
			 |  
			 
			 |  
			  Abstract
			  
			       The genesis of this paper is the construction
of a new operator that, when combined
with  a theorem of Herrero,  settles a
question  of Herrero.  Herrero proved that a strictly
cyclic operator on an infinite
dimensional Hilbert space is never triangular.
He  later asks
whether the adjoint of a strictly cyclic operator
is necessarily triangular.  We settle the
question by constructing an operator T for which
both T and T* are strictly cyclic.  We make a
detailed study of this  bi-strictly cyclic operator
which leads to theorems about general bi-strictly cyclic
operators.  We conclude the paper with a comparison of
the operator space structures of the singly
generated algebras A(S) and A(T),
when S is strictly cyclic and T is bi-strictly cyclic.
   | 
           
			
			  
			      
		       | 
		   
			
			  | Author information
 John Froelich: 
Department of Mathematics, University of Houston, University Park, Houston, Texas 77204 
JohnF12748@aol.com 
Ben Mathes: 
Department of Mathematics & Computer Science, Colby College, Waterville, ME  04901 
dbmathes@colby.edu 
   | 
		   
         
       |