Abstract
             | 
           
          
            | 
 For a given positive integer 
,
 we determine an explicit infinite family of real quadratic number fields
 
,
 such that the unramified abelian Iwasawa module over the
 
-extension
 of 
, is
 isomorphic to 
.
  
 | 
           
         
        
          
            
              Keywords
              
                class group, unit group, capitulation problem,
                $Z_2$-extension
               
             | 
           
         
        
          
            
              Mathematical Subject Classification
              
                Primary: 11R23, 11R29, 11R32, 11R37
               
             | 
           
         
        
          
            
              Milestones
              
                Received: 25 October 2022
               
              
                Revised: 28 February 2023
               
              
                Accepted: 1 April 2023
               
              
                Published: 29 May 2023
               
             | 
           
         
        
        
        
          
            | © 2023 MSP (Mathematical Sciences
            Publishers). Distributed under the Creative Commons
            Attribution License 4.0 (CC BY). | 
           
         
        Open Access made possible by participating
        institutions via Subscribe to Open.  
       |