Waveguide with double threshold~resonance at a~simple threshold
    
    
  
  
  
      
      
      
        
Sbornik. Mathematics, Tome 211 (2020) no. 8, pp. 1080-1126
    
  
  
  
  
  
    
      
      
        
      
      
      
    Voir la notice de l'article provenant de la source Math-Net.Ru
            
              			A threshold resonance generated by an almost standing wave occurring at a threshold — a solution of the problem that do not decay at infinity, but rather stabilizes there — brings about various anomalies in the diffraction pattern at near-threshold frequencies. Examples when a simple threshold resonance occurs or does not occur are trivial. For the first time an acoustic waveguide (the Neumann spectral problem for the Laplace operator) of a special shape is constructed in which there is a maximum possible number (namely two) of linearly independent almost standing waves at a threshold (equal to a simple eigenvalue of the model problem on the cross-section of the cylindrical outlets to infinity). Effects in the scattering problem for acoustic waves, which are caused by these standing waves are discussed. 
Bibliography: 54 titles.
			
            
            
            
          
        
      
                  
                    
                    
                    
                        
Keywords: 
acoustic waveguide, double threshold resonance, almost standing waves, asymptotic analysis, near-threshold anomalies, weighted spaces with detached asymptotics.
                    
                    
                    
                  
                
                
                @article{SM_2020_211_8_a1,
     author = {S. A. Nazarov},
     title = {Waveguide with double threshold~resonance at a~simple threshold},
     journal = {Sbornik. Mathematics},
     pages = {1080--1126},
     publisher = {mathdoc},
     volume = {211},
     number = {8},
     year = {2020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2020_211_8_a1/}
}
                      
                      
                    S. A. Nazarov. Waveguide with double threshold~resonance at a~simple threshold. Sbornik. Mathematics, Tome 211 (2020) no. 8, pp. 1080-1126. http://geodesic.mathdoc.fr/item/SM_2020_211_8_a1/
