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  JOSEPH FELS RITT LECTURES
         
         
Freydoon Shahidi
  Purdue
  
  
 
Functoriality Principle and the Spectral Theory of Automorphic Functions
                      
        Abstract:  In  these   
  two  lectures we start by explaining a number of   
  problems
                             
  in   arithmetic  and   spectral   
  theory   of   automorphic  functions  both   
  on   the
                             
  Poincare   and   Siegel   half   
  spaces   and   their  generalizations. We then 
  show
                             
  how   they   can   be   resolved   
  by   appealing   to   certain   cases  
  of Langlands
                             
  functoriality  conjecture   which   allows   
  these   functions   to   be   
  transfered to
                             
  functions   on   spaces   of higher dimension in 
  a canonical way.  These transfers
                             
  are   now established by the speaker and his collaborator in a 
  number of   cases.
                             
  Our   discussion   will   include   
  the  recent developements on the conjectures of
                             
  Ramanujan   and Selberg for   Maass forms, as well as 
  their generalizations   to
                             
  more general groups. We will also explain  how these results lead to new   
  cases
                             
  of Artin conjecture as well as to the existence of Siegel modular forms of 
  weight
                             
  3   and   other  arithmetic and spectral results.    
  We  conclude  these lectures by
                             
  sketching    in    a   simple   
  language   how   these    transfers   
  are   established.
  Thursday, April 21
  
         
         
         
         
  312 
  Mathematics Building
         
         
         
         This Lecture will be at 5:30 p.m.
         Tea will be served at 4:45 p.m., in 
         
         
         
         
         
  508 
  Mathematics Bldg.
  
  and
  
         
  
         Friday, April 22
  
         
         
         
         
  312 
  Mathematics Building
  
         
         
         
         This Lecture will be at 4:30 p.m.
         Tea will be served at 3:45 p.m., in 
         
         
         
         
         
  508 
  Mathematics Bldg.